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13 pages, 26305 KiB

Open AccessArticle

Stabilizing Effect of Soluplus on Erlotinib Metastable Crystal Form in Microparticles and Amorphous Solid Dispersions

by Shuyu Jia, Shangqi Ning, Yuting Leng, Qiufang Jing, Zhongyu Xu and Fuzheng Ren

Polymers 2022, 14(6), 1241; https://doi.org/10.3390/polym14061241 - 19 Mar 2022

Cited by 8 | Viewed by 2727

Abstract

Microparticles (MPs) and amorphous solid dispersions (SDs) are effective methods to improve the dissolution of insoluble drugs. However, stability is a concern for these two high-energy systems, resulting from high surface area and amorphous polymorph, respectively. As an amphiphilic polymer, Soluplus (SOL) is [...] Read more.

Microparticles (MPs) and amorphous solid dispersions (SDs) are effective methods to improve the dissolution of insoluble drugs. However, stability is a concern for these two high-energy systems, resulting from high surface area and amorphous polymorph, respectively. As an amphiphilic polymer, Soluplus (SOL) is usually used as a carrier in SDs. In this study, erlotinib microparticles (ERL MPs) and erlotinib solid dispersions (ERL SDs) were prepared with SOL by bottom-up technology and solvent evaporation. The solid-state properties of ERL MPs and ERL SDs were characterized by Differential Scanning Calorimetry (DSC), Powder X-Ray Diffraction (PXRD) and Scanning Electron Microscopy (SEM). The ERL MPs existed in a metastable crystal form A while the ERL SDs existed in an amorphous state. Fourier transform infrared spectroscopy (FT-IR) showed that there was a hydrogen bond interaction between the N-H group of ERL and the carbonyl group of SOL in ERL MPs and SDs. The dissolution profiles of ERL SDs and ERL MPs were improved significantly. ERL MPs showed better stability than ERL SDs in accelerated stability test. The discrepant stabilizing effects of polymer SOL in two systems may provide effective ideas for solubilization of insoluble drugs and the stability of drugs after recrystallization. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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10 pages, 3010 KiB

Open AccessArticle

Physico-Mechanical Properties of Commercially Available Tissue Conditioner Modified with Synthesized Chitosan Oligosaccharide

by Asfia Saeed, Shahreen Zahid, Muhammad Sajid, Shahab Ud Din, Mohammad Khursheed Alam, Farooq Ahmad Chaudhary, Muhammad Kaleem, Haytham Jamil Alswairki and Huda Abutayyem

Polymers 2022, 14(6), 1233; https://doi.org/10.3390/polym14061233 - 18 Mar 2022

Cited by 10 | Viewed by 2219

Abstract

This study aims to compare the hardness, sorption and solubility of commercially available tissue conditioner [TC] modified with chitosan [CS] and synthesized chitosan oligosaccharide [COS] in antifungal concentration. COS was synthesized by acid hydrolysis and characterized by FTIR and XRD. Experimental materials were [...] Read more.

This study aims to compare the hardness, sorption and solubility of commercially available tissue conditioner [TC] modified with chitosan [CS] and synthesized chitosan oligosaccharide [COS] in antifungal concentration. COS was synthesized by acid hydrolysis and characterized by FTIR and XRD. Experimental materials were formulated by incorporating each per gram of TC powder with effective antifungal concentration of chitosan 1.02 mg (Group 1: TC-CS) and 0.51 mg COS (Group 2: TC-COS). A commercially available TC was used as control (Group 0: CTC). Shore A hardness test was performed according to ASTM D 2240-05 (2010) standards on samples stored in dry environment, distilled water (DW) and artificial saliva (AS) at 37 °C (n = 5 per group). Percent weight changes (n = 5 per group) after storage in DW and AS was used to record sorption and solubility. One-way Anova with post hoc Tukey’s test was applied. FTIR and XRD confirmed low molecular weight and amorphous nature of COS. Experimental groups had higher Shore A hardness values; however, these changes were not significant. Greatest variations in durometer values (p ≤ 0.05) were observed during the first 24 h. Experimental groups had higher (p ≤ 0.05) percentage sorption and solubility. Samples stored in DW had significantly higher (p = 0.019) sorption, whereas material had higher (p = 0.005) solubility in AS. Mean solubility values in both immersion mediums was highest for Group 2, followed by group 1 and group 0. In addition, significant (p ≤ 0.05) increase in solubility upon aging was noted for each material. Experimental tissue conditioner had higher hardness, sorption and solubility. However, these changes are not substantial to interfere with their tissue healing property. Therefore, these materials may be considered and explored further as potential antimicrobial drug delivery agent for denture stomatitis patients. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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10 pages, 1188 KiB

Open AccessArticle

Influence of Conventional Polymer, Hybrid Polymer and Zinc Phosphate Luting Agents on the Bond Strength of Customized Zirconia Post in Premolars—An In-Vitro Evaluation

by Khulud A. AlAali, Abdulaziz AlHelal, Jawaher R. Almahri, Aroob A. Albakri, Ragad M. Albani, Yasmeen A. Alhaizan, Mai M. Alhamdan, Naif A. Alaql, Mashael Binhasan, Eman M. Alhamdan, Ahmed H. Albaqawi, Fahim Vohra and Tariq Abduljabbar

Polymers 2022, 14(4), 758; https://doi.org/10.3390/polym14040758 - 15 Feb 2022

Cited by 6 | Viewed by 2022

Abstract

The aim was to identify the influence of conventional polymeric resin based cement (RC), hybrid polymer modified glass ionomer (RMGIC) and Zinc phosphate cement (ZPC) on the pull out strength of the customized zirconia post in premolars. Access cavity and root canals were [...] Read more.

The aim was to identify the influence of conventional polymeric resin based cement (RC), hybrid polymer modified glass ionomer (RMGIC) and Zinc phosphate cement (ZPC) on the pull out strength of the customized zirconia post in premolars. Access cavity and root canals were performed in sixty premolar teeth with the standardized crown down technique (ProTaper Universal, Dentsply). Post space impressions were scanned, and the pre-sintered Zenostar Zr Translucent blanks (Weiland Dental, Pforzheim) were milled with the Opera-system to form the post. All prepared specimens were divided equally in three groups based on the cement type employed for luting as follows: group A: ZPC; group B (GC Fuji PLUS Capsule): RMGIC; group C (and RC (3M RelyX ARC). Ten specimens in each group were thermocycled (TC) at 5 and 55 °C in distilled water baths (40,000 cycles). Pull out bond strength was assessed using a universal testing machine at 0.5 mm/min. The means and standard deviations were compared using ANOVA and Tukey Kramer multiple comparisons tests. A significant difference among the cement groups as well as between TC and non-thermocycled (NTC) groups (p < 0.05) was observed. The highest tensile stress was demonstrated among group C (Resin, 69.89 ± 4.81 (NTC), 64.06 ± 4.36 (TC)) with the least in group A, (zinc phosphate, 43.66 ± 5.02 (NTC), 37.70 ± 5.10 (TC)) for both groups. Group A presented with 100% adhesive bond failures, followed by 80% in group C and 70% in group B, respectively. A similar outcome was observed in the TC group for the cement; however, unlike the NTC group, the TC group showed more cohesive failures compared to the NTC mixed failure. Dual cure polymer based cement demonstrated higher bond strength and efficient adhesive bonding of the customized Zr post with root dentine compared to zinc phosphate (non-polymeric) and RMGIC (hybrid polymer). Thermocycling compromised Zr post adhesive bonding to root dentin. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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21 pages, 34111 KiB

Open AccessArticle

Solubility and Dissolution Enhancement of Dexibuprofen with Hydroxypropylbetacyclodextrin (HPβCD) and Poloxamers (188/407) Inclusion Complexes: Preparation and In Vitro Characterization

by Rabia Munir, Abdul Hadi, Salah-ud-Din Khan, Sajid Asghar, Muhammad Irfan, Ikram Ullah Khan, Misbah Hameed, Sana Inam, Nayyer Islam, Shahzadi Filza Hassan, Memoona Ishtiaq, Pervaiz Akhtar Shah, Muhammad Shahid Iqbal, Haroon Khalid Syed, Ahmed Khames and Mohammad A. S. Abourehab

Polymers 2022, 14(3), 579; https://doi.org/10.3390/polym14030579 - 31 Jan 2022

Cited by 17 | Viewed by 3715

Abstract

The objective of this study was to improve the dissolution and solubility of dexibuprofen (DEX) using hydroxypropyl beta cyclodextrin (HPβCD) inclusion complexes and also to evaluate the effect of presence of hydrophilic polymers on solubilization efficiency of HPβCD. Three different methods (physical trituration, [...] Read more.

The objective of this study was to improve the dissolution and solubility of dexibuprofen (DEX) using hydroxypropyl beta cyclodextrin (HPβCD) inclusion complexes and also to evaluate the effect of presence of hydrophilic polymers on solubilization efficiency of HPβCD. Three different methods (physical trituration, kneading and solvent evaporation) were used to prepare binary inclusion complexes at various drug-to-cyclodextrin weight ratios. An increase in solubility and drug release was observed with the kneading (KN) method at a DEX/HPβCD (1:4) weight ratio. The addition of hydrophilic polymers poloxamer-188 (PXM-188) and poloxamer-407 (PXM-407) at 2.5, 5.0, 10.0 and 20% w/w enhanced the complexation efficiency and solubility of DEX/HPβCD significantly. Fourier-transform infrared (FTIR) analysis revealed that DEX was successfully incorporated into the cyclodextrin cavity. Differential scanning calorimetry (DSC) and X-ray diffractometry (XRD) revealed less crystallinity of the drug and its entrapment in the cyclodextrin molecular cage. The addition of PXM-188 or PXM-407 reduced the strength of the DEX endothermic peak. With the addition of hydrophilic polymers, sharp and intense peaks of DEX disappeared. Finally, it was concluded that PXM-188 at a weight ratio of 10.0% w/w was the best candidate for improving solubility, stability and release rate of DEX. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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23 pages, 13625 KiB

Open AccessArticle

Metronidazole Based Floating Bioadhesive Drug Delivery System for Potential Eradication of H. pylori: Preparation and In Vitro Characterization

by Faiza Naseem, Shefaat Ullah Shah, Sheikh Abdur Rashid, Arshad Farid, Mazen Almehmadi and Saad Alghamdi

Polymers 2022, 14(3), 519; https://doi.org/10.3390/polym14030519 - 27 Jan 2022

Cited by 20 | Viewed by 4431

Abstract

Metronidazole has the potential to produce local stomach specific action in order to treat Helicobacter pylori induced peptic ulcer disease. The current project executes the development of osmotically controlled bioadhesive metronidazole loaded effervescent floating tablets with optimized floating and swelling behavior. Direct compression [...] Read more.

Metronidazole has the potential to produce local stomach specific action in order to treat Helicobacter pylori induced peptic ulcer disease. The current project executes the development of osmotically controlled bioadhesive metronidazole loaded effervescent floating tablets with optimized floating and swelling behavior. Direct compression technique was used to prepare the tablets. The designed formulations exhibited physico-chemical properties within acceptable optimum limits as per pharmacopeial requirements. The results of tablet floating studies revealed that all formulations, except F1 and F5, had good buoyancy characteristics (TFT > 12 h except F2 and F8 with TFT of 6 h). Formulation F2 containing guar gum in higher concentration with carbopol and formulation F8 containing guar gum in 50% decreased concentration in combination with HPMC and carbopol had enhanced FLT appreciably, with least TFT as compared to formulations F3, F4, and F6 (ANOVA; p ≤ 0.05). Formulation batches of F3, F4, and F6 exhibited appreciable FLT as well as TFT and were optimized formulations. Out of the above mentioned optimized batches, F4 and F6 formulations showed low FLT (4 and 5 s respectively). The results of the swelling study indicated a proportionate increase in the swelling index with increase in time. A significantly higher swelling ratio was found with formulation F6 and F4 compared with that of F7 and F8 (ANOVA; p ≤ 0.05). Additionally, the impact of pH change, agitational intensity, as well as increasing concentration of NaCl was investigated on drug release. It was observed that agitational intensity had no effect on drug release rate while increasing concentration of NaCl produced an increased drug release from the dosage form as compared to the drug release exhibited by the formulations in the absence of NaCl. Overall, this project could have valuable contribution in the fabrication of metronidazole loaded effervescent floating tablets. Gastro-retentive systems are expected to enhance local stomach specific action of anti H. pylori agents based on their buoyancy and swelling behavior. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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14 pages, 1920 KiB

Open AccessArticle

Preparation and Characterization of Antibacterial Films with Eggshell-Membrane Biopolymers Incorporated with Chitosan and Plant Extracts

by Brian Cameron Wooding Webb, Steven Rafferty and Andrew James Vreugdenhil

Polymers 2022, 14(3), 383; https://doi.org/10.3390/polym14030383 - 19 Jan 2022

Cited by 9 | Viewed by 2874

Abstract

A series of films containing chitosan (CS), eggshell membrane (ESM), soluble eggshell membrane (SEP), and plant extracts from Thymus vulgaris and Origanum valgare were prepared with varying concentrations and compositions. These novel films were characterized extensively with respect to film thickness and uniformity, [...] Read more.

A series of films containing chitosan (CS), eggshell membrane (ESM), soluble eggshell membrane (SEP), and plant extracts from Thymus vulgaris and Origanum valgare were prepared with varying concentrations and compositions. These novel films were characterized extensively with respect to film thickness and uniformity, solution absorption, degradation, microenvironmental pH, and antibacterial properties. All the films were flexible with appropriate mechanical stability. After 48 h of soaking in a lysozyme solution, all the films degraded 64 ± 4%, which would be expected to allow for the release of the plant extracts. The plant extracts on their own showed a pH of approximately 4, with the blended films having microenvironmental pHs from approximately 6.4–7.0, which would be expected to promote wound healing. A CS-ESM-SEP film with 5% of each plant extract inhibited almost all E. coli growth in liquid cultures and had no detriments to fluid absorption. Fluid absorption was approximately 100–150% by weight for all the films. The incorporation of SEP and plant extracts to a CS-ESM film provides a promising and novel method for the incorporation of SEP and antibacterial agents in a film with no detriment to wound fluid absorption or film degradation. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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10 pages, 1059 KiB

Open AccessArticle

Water Sorption, Water Solubility, and Rheological Properties of Resin-Based Dental Composites Incorporating Immobilizable Eugenol-Derivative Monomer

by Ali Alrahlah, Abdel-Basit Al-Odayni, Waseem Sharaf Saeed, Abdullah Al-Kahtani, Fahad M. Alkhtani and Nassr S. Al-Maflehi

Polymers 2022, 14(3), 366; https://doi.org/10.3390/polym14030366 - 18 Jan 2022

Cited by 7 | Viewed by 2604

Abstract

The present study aimed to evaluate the properties of new dental formulations incorporating a new polymerizable-derivative of eugenol (EgGMA). The experimental composites were prepared (by weight) with 35% resin-based matrix (1:1, bisphenol A-glycidyl methacrylate/triethylene glycol dimethacrylate) and 65% reinforcing materials (4:3, hydroxyapatite/zirconium oxide). [...] Read more.

The present study aimed to evaluate the properties of new dental formulations incorporating a new polymerizable-derivative of eugenol (EgGMA). The experimental composites were prepared (by weight) with 35% resin-based matrix (1:1, bisphenol A-glycidyl methacrylate/triethylene glycol dimethacrylate) and 65% reinforcing materials (4:3, hydroxyapatite/zirconium oxide). A portion of 0.0, 2.5, and 5.0% of the resins with respect to the total composite was replaced by EgGMA monomer to obtain TBEg0, TBEg2.5, and TBEg5, respectively. The complex viscosity (at 25 and 37 °C), degree of conversion (DC), and water sorption (W_SP) and water solubility (W_SL) (3 cycles of sorption-desorption process) were investigated. Data were statistically analyzed using one-way and Tukey post-hoc tests. The results revealed a viscosity reduction with shear-thinning behavior as the EgGMA amount and temperature increased. The average complex viscosities at a lower frequency (ω = 1.0 rad/s) and at 25 °C were 234.7 ± 13.4, 86.4 ± 16.5, and 57.3 ± 17.1 (kPa·s) for TBEg0, TBEg2.5, and TBEg5, respectively. The inclusion of EgGMA led to a lower DC and W_SP but higher W_SL, compared to those of the reference (TBEg0). However, no significant differences between TBEg2.5 and control were detected (p > 0.05). Therefore, the incorporation of EgGMA in a low quantity, e.g., up to 8.45 mol% of resins, within the matrix may enhance the composite’s performance, including handling and solubility properties without any apparent effect on DC and water sorption, making it a promising monomeric biomaterial for various applications including restorative dentistry. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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12 pages, 4666 KiB

Open AccessArticle

Polymer-Based Bioactive Luting Agents for Cementation of All-Ceramic Crowns: An SEM, EDX, Microleakage, Fracture Strength, and Color Stability Study

by Samer Al-Saleh, Turki W. Aboghosh, Mousa S. Hazazi, Khalid A. Binsaeed, Abdulaziz M. Almuhaisen, Huda I. Tulbah, Amal S. Al-Qahtani, Sara Shabib, Mashael Binhasan, Fahim Vohra and Tariq Abduljabbar

Polymers 2021, 13(23), 4227; https://doi.org/10.3390/polym13234227 - 2 Dec 2021

Cited by 4 | Viewed by 2216

Abstract

The aim of the study was to compare microleakage and fracture loads of all ceramic crowns luted with conventional polymer resins and polymeric bioactive cements and to assess the color stability of polymeric bioactive cements. Seventy-five extracted premolar teeth were tested for fracture [...] Read more.

The aim of the study was to compare microleakage and fracture loads of all ceramic crowns luted with conventional polymer resins and polymeric bioactive cements and to assess the color stability of polymeric bioactive cements. Seventy-five extracted premolar teeth were tested for fracture loads and microleakage in all-ceramic crowns cemented with two types of polymeric bioactive cements and resin cements. In addition, the degree of color change for each cement with coffee was assessed. Thirty maxillary premolar teeth for fracture loads and thirty mandibular premolar teeth for microleakage were prepared; standardized teeth preparations were performed by a single experienced operator. All prepared specimens were randomly distributed to three groups (n = 20) based on the type of cement, Group 1: resin cement (Multilink N); Group 2: polymeric bioactive cement (ACTIVA); Group 3: polymeric bioactive cement (Ceramir). The cementation procedures for all cements (Multilink, ACTIVA, and Ceramir) were performed according to the manufacturers’ instructions. All specimens were aged using thermocycling for 30,000 cycles (5–55 °C, dwell time 30 s). These specimens were tested using the universal testing machine for fracture strength and with a micro-CT for microleakage. For the color stability evaluation, the cement specimens were immersed in coffee and evaluated with a spectrometer. Results: The highest and lowest means for fracture loads were observed in resin cements (49.5 ± 8.85) and Ceramir (39.8 ± 9.16), respectively. Ceramir (2.563 ± 0.71) showed the highest microleakage compared to resin (0.70 ± 0.75) and ACTIVA (0.61 ± 0.56). ACTIVA cements showed comparable fracture loads, microleakage, and stain resistance compared to resin cements. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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20 pages, 1747 KiB

Open AccessArticle

Germanium-Titanium-π Polymer Composites as Functional Textiles for Clinical Strategy to Evaluate Blood Circulation Improvement and Sexual Satisfaction

by Yu-Cing Juho, Shou-Hung Tang, Yi-Hsin Lin, Chen-Xi Lin, Tenson Liang, Juin-Hong Cherng and En Meng

Polymers 2021, 13(23), 4154; https://doi.org/10.3390/polym13234154 - 27 Nov 2021

Cited by 3 | Viewed by 2896

Abstract

By continuously enhancing the blood flow, far-infrared (FIR) textile is anticipated to be a potential non-pharmacological therapy in patients with peripheral vascular disorders, for instance, patients with end-stage renal disease (ESRD) undergoing hemodialysis (HD) and experiencing vasculogenic erectile dysfunction (VED). Hence, we manufactured [...] Read more.

By continuously enhancing the blood flow, far-infrared (FIR) textile is anticipated to be a potential non-pharmacological therapy in patients with peripheral vascular disorders, for instance, patients with end-stage renal disease (ESRD) undergoing hemodialysis (HD) and experiencing vasculogenic erectile dysfunction (VED). Hence, we manufactured a novel polymer composite, namely, germanium-titanium-π (Ge-Ti-π) textile and aimed to evaluate its characteristics and quality. We also investigated the immediate and long-term effects of the textile on patients with ESRD undergoing HD and experiencing VED. The Ge-Ti-π textile was found to have 0.93 FIR emissivity, 3.05 g/d strength, and 18.98% elongation. The results also showed a 51.6% bacteria reduction and negative fungal growth. On application in patients receiving HD, the Ge-Ti-π textile significantly reduced the limb numbness/pain (p < 0.001) and pain score on the visual analog scale (p < 0.001). Moreover, the Doppler ultrasound assessment data indicated a significant enhancement of blood flow in the right hand after 1 week of Ge-Ti-π textile treatment (p < 0.041). In VED patients, the Ge-Ti-π underpants treatment significantly improved the quality of sexual function and increased the average penile blood flow velocity after 3 months of the treatment. Our study suggests that the Ge-Ti-π textile could be beneficial for patients with blood circulation disorders. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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24 pages, 10420 KiB

Open AccessArticle

The Effect of Agarose on 3D Bioprinting

by Chi Gong, Zhiyuan Kong and Xiaohong Wang

Polymers 2021, 13(22), 4028; https://doi.org/10.3390/polym13224028 - 21 Nov 2021

Cited by 28 | Viewed by 3739

Abstract

In three-dimensional (3D) bioprinting, the accuracy, stability, and mechanical properties of the formed structure are very important to the overall composition and internal structure of the complex organ. In traditional 3D bioprinting, low-temperature gelatinization of gelatin is often used to construct complex tissues [...] Read more.

In three-dimensional (3D) bioprinting, the accuracy, stability, and mechanical properties of the formed structure are very important to the overall composition and internal structure of the complex organ. In traditional 3D bioprinting, low-temperature gelatinization of gelatin is often used to construct complex tissues and organs. However, the hydrosol relies too much on the concentration of gelatin and has limited formation accuracy and stability. In this study, we take advantage of the physical crosslinking of agarose at 35–40 °C to replace the single pregelatinization effect of gelatin in 3D bioprinting, and printing composite gelatin/alginate/agarose hydrogels at two temperatures, i.e., 10 °C and 24 °C, respectively. After in-depth research, we find that the structures manufactured by the pregelatinization method of agarose are significantly more accurate, more stable, and harder than those pregelatined by gelatin. We believe that this research holds the potential to be widely used in the future organ manufacturing fields with high structural accuracy and stability. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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11 pages, 4635 KiB

Open AccessArticle

Characterization and Topical Study of Aloe Vera Hydrogel on Wound-Healing Process

by Karen Zulema Meza-Valle, Rosa Alicia Saucedo-Acuña, Karla Lizzette Tovar-Carrillo, Juan Carlos Cuevas-González, Erasto Armando Zaragoza-Contreras and Juana Melgoza-Lozano

Polymers 2021, 13(22), 3958; https://doi.org/10.3390/polym13223958 - 16 Nov 2021

Cited by 16 | Viewed by 5929

Abstract

Wound healing is fundamental to restore the tissue integrity. A topical study of the influence of Aloe vera hydrogel, formulated with 1,2-propanediol (propanediol) and triethanolamine (TEA), on the skin wound-healing process was investigated in female Wistar rats. FTIR spectroscopy confirms the presence of [...] Read more.

Wound healing is fundamental to restore the tissue integrity. A topical study of the influence of Aloe vera hydrogel, formulated with 1,2-propanediol (propanediol) and triethanolamine (TEA), on the skin wound-healing process was investigated in female Wistar rats. FTIR spectroscopy confirms the presence of carboxylic acid and methyl ester carboxylate groups related with important compounds that confer the hydrogel a good interaction with proteins and growth factors. SEM images show a microstructure and micro-roughness that promote a good adhesion to the wound. Therefore, the swelling kinetics and the contact angle response contribute to the understanding of the in vivo results of the animal test. The results indicated that the Aloe vera hydrogel, prepared with propanediol and TEA, together with its superficial characteristics, improve its rapid penetration without drying out the treated tissue. This produced a positive influence on inflammation, angiogenesis, and wound contraction, reducing 29% the total healing time, reaching the total closure of the wound in 15 days. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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22 pages, 7539 KiB

Open AccessArticle

PMMA Bone Cements Modified with Silane-Treated and PMMA-Grafted Hydroxyapatite Nanocrystals: Preparation and Characterization

by Do Quang Tham, Mai Duc Huynh, Nguyen Thi Dieu Linh, Do Thi Cam Van, Do Van Cong, Nguyen Thi Kim Dung, Nguyen Thi Thu Trang, Pham Van Lam, Thai Hoang and Tran Dai Lam

Polymers 2021, 13(22), 3860; https://doi.org/10.3390/polym13223860 - 9 Nov 2021

Cited by 16 | Viewed by 3988

Abstract

In this study, vinyltrimethoxysilane-treated hydroxyapatite (vHAP) and PMMA-grafted HAP (gHAP) were successfully prepared from original HAP (oHAP). Three kinds of HAP (oHAP, vHAP and g HAP) were used as additives for the preparation of three groups of HAP-modified PMMA bone cements (oHAP-BC, vHAP-BC [...] Read more.

In this study, vinyltrimethoxysilane-treated hydroxyapatite (vHAP) and PMMA-grafted HAP (gHAP) were successfully prepared from original HAP (oHAP). Three kinds of HAP (oHAP, vHAP and g HAP) were used as additives for the preparation of three groups of HAP-modified PMMA bone cements (oHAP-BC, vHAP-BC and gHAP-BC). The setting, bending and compression properties of the bone cements were conducted according to ISO 5833:2002. The obtained results showed that the maximum temperature while curing the HAP-modified bone cements (HAP-BCs) decreased from 64.9 to 60.8 °C and the setting time increased from 8.1 to 14.0 min, respectively, with increasing HAP loading from 0 to 15 wt.%. The vHAP-BC and gHAP-BC groups exhibited higher mechanical properties than the required values in ISO 5833. Electron microscopy images showed that the vHAP and gHAP nanoparticles were dispersed better in the polymerized PMMA matrix than the oHAP nanoparticles. FTIR analysis indicated the polar interaction between the PO₄ groups of the HAP nanoparticles and the ester groups of the polymerized PMMA matrix. Thermal gravimetric analysis indicated that mixtures of ZrO₂/HAPs were not able to significantly improve the thermal stability of the HAP-BCs. DSC diagrams showed that the incorporation of gHAP to PMMA bone cement with loadings lower than 10 wt.% can increase T_g by about 2.4 °C. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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9 pages, 2189 KiB

Open AccessCommunication

Functional or Nonfunctional Cusps Preservation for Molars Restored with Indirect Composite or Glass-Ceramic Onlays: 3D FEA Study

by Pablo Lenin Benitez Sellan, Larissa Mendes Campaner, João Paulo Mendes Tribst, Amanda Maria de Oliveira Dal Piva, Guilherme Schmitt de Andrade, Alexandre Luiz Souto Borges, Eduardo Bresciani, Antonio Lanzotti and Pietro Ausiello

Polymers 2021, 13(21), 3831; https://doi.org/10.3390/polym13213831 - 5 Nov 2021

Cited by 3 | Viewed by 2854

Abstract

Evidence regarding the effect of the onlay preparation design for different CAD/CAM restorative materials considering the preservation of cusps is lacking. Molars were 3D-modeled in four preparation designs for onlay restoration: traditional design with functional cusp coverage (TFC), non-retentive design with functional cusp [...] Read more.

Evidence regarding the effect of the onlay preparation design for different CAD/CAM restorative materials considering the preservation of cusps is lacking. Molars were 3D-modeled in four preparation designs for onlay restoration: traditional design with functional cusp coverage (TFC), non-retentive design with functional cusp coverage (NFC), traditional design with non-functional cusp coverage (TNFC) and non-retentive design with non-functional cusp coverage (NNFC). The restorations were simulated with two CAD/CAM restorative materials: LD—lithium disilicate (IPS e.max CAD) and RC—resin composite (GrandioBloc). A 100 N axial load was applied to the occlusal surface, simulating the centric contact point. Von Mises (VM) and maximum principal (Pmax) stress were evaluated for restorations, cement layer and dental substrate. The non-retentive preparation design reduced the stress concentration in the tooth structure in comparison to the conventional retentive design. For LD onlays, the stress distribution on the restoration intaglio surface showed that the preparation design, as well as the prepared cusp, influenced the stress magnitude. The non-retentive preparation design provided better load distribution in both restorative materials and more advantageous for molar structure. The resin composite restoration on thenon-functional cusp is recommended when the functional cusp is preserved in order to associate conservative dentistry and low-stress magnitude. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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13 pages, 2308 KiB

Open AccessArticle

Influence of TiO₂ and ZrO₂ Nanoparticles on Adhesive Bond Strength and Viscosity of Dentin Polymer: A Physical and Chemical Evaluation

by Samar Al-Saleh, Abdullah Alateeq, Abdulaziz H. Alshaya, Amal S. Al-Qahtani, Huda I. Tulbah, Mashael Binhasan, Sara Shabib, Imran Farooq, Fahim Vohra and Tariq Abduljabbar

Polymers 2021, 13(21), 3794; https://doi.org/10.3390/polym13213794 - 2 Nov 2021

Cited by 22 | Viewed by 2921

Abstract

The present study aimed to formulate an experimental adhesive (EA) and reinforce it with 5 wt.% titanium dioxide (TiO₂) or zirconium oxide (ZrO₂) to yield 5% TiO₂ and 5% ZrO₂ adhesives, respectively, and then analyze the impact [...] Read more.

The present study aimed to formulate an experimental adhesive (EA) and reinforce it with 5 wt.% titanium dioxide (TiO₂) or zirconium oxide (ZrO₂) to yield 5% TiO₂ and 5% ZrO₂ adhesives, respectively, and then analyze the impact of this reinforcement on various mechanical properties of the adhesives. The EA contained a blend of monomers such as bisphenol A glycol dimethacrylate (BisGMA), triethylene glycol dimethacrylate (TEGDMA), 2-hydroxyethyl methacrylate (HEMA), and ethyl 4-dimethylamino benzoate and camphorquinone. The EA included ethyl 4-dimethylamino benzoate and camphorquinone photo-initiators, and diphenyliodonium hexafluorophosphate (DPIHP) was also included to act as an electron initiator. The TiO₂ and ZrO₂ nanoparticles were incorporated into the EA post-synthesis. To characterize the filler nanoparticles, scanning electron microscopy (SEM) and line-energy dispersive X-ray (EDX) spectroscopy were performed. The adhesives were characterized by analyzing their rheological properties, shear-bond strength (SBS), and interfacial failure types. Further, the resin–dentin interface was also analyzed via SEM. The TiO₂ nanoparticles were spherically shaped on the SEM micrographs, while the ZrO₂ nanoparticles were seen as non-uniformly shaped agglomerates. The EDX mapping demonstrated the presence of Ti and oxygen for TiO₂ and Zr and oxygen for the ZrO₂ nanoparticles. Both 5% TiO₂ and 5% ZrO₂ adhesives revealed decreased viscosity as compared with the EA. The 5% TiO₂ adhesive demonstrated higher SBS values for both non-thermocycled (NTC) and thermocycled samples (NTC: 25.35 ± 1.53, TC: 23.89 ± 1.95 MPa), followed by the 5% ZrO₂ adhesive group (NTC: 23.10 ± 2.22, TC: 20.72 ± 1.32 MPa). The bulk of the failures (>70%) were of adhesive type in all groups. The SEM analysis of the resin–dentin interface revealed the development of a hybrid layer and resin tags (of variable depth) for the EA and 5% TiO₂ groups. However, for the 5% ZrO₂ group, the hybrid layer and resin tag establishment appeared compromised. Reinforcement of the EA with TiO₂ or ZrO₂ caused an increase in the adhesive’s SBS (with the 5% TiO₂ group demonstrating the highest values) in comparison with the EA (without nanoparticles). However, both nanoparticle-containing adhesives revealed decreased viscosity compared with the EA (without nanoparticles). Further studies investigating the impact of diverse filler concentrations on the properties of adhesives are suggested. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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13 pages, 3385 KiB

Open AccessArticle

Influence of Toothbrush Abrasion and Surface Treatments on Roughness and Gloss of Polymer-Infiltrated Ceramics

by Nawaf Labban, Mohammad D. Al Amri, Sarah M. Alnafaiy, Saleh M. Alhijji, Mohammad A. Alenizy, Mounir Iskandar and Sabrina Feitosa

Polymers 2021, 13(21), 3694; https://doi.org/10.3390/polym13213694 - 27 Oct 2021

Cited by 8 | Viewed by 2145

Abstract

The aim of this study was to compare the surface roughness and gloss of polymer-infiltrated ceramics after simulated in vitro toothbrushing in different storage mediums. Four polymer- infiltrated ceramics were evaluated, Lava ultimate (LU), Vita enamic (EN), Shofu (SH), and Crystal ultra (CU). [...] Read more.

The aim of this study was to compare the surface roughness and gloss of polymer-infiltrated ceramics after simulated in vitro toothbrushing in different storage mediums. Four polymer- infiltrated ceramics were evaluated, Lava ultimate (LU), Vita enamic (EN), Shofu (SH), and Crystal ultra (CU). The control group was a feldspathic ceramic, Vita Mark II (VM). One hundred and twenty specimens (12 × 14 × 2.5 mm) were prepared using a precision saw. For each material (n = 24), the specimens were allocated into two groups, polished and stained. The specimens of each group were stored (for 7 days) in either citric acid (0.2N) or distilled water. Data for surface gloss (ΔE*_SCE-SCI) and roughness (Ra) were evaluated before (baseline) and after simulated toothbrushing. For toothbrushing simulation, a toothpaste slurry containing a toothpaste of 100 relative dentin abrasion (RDA) and 0.3 ml distilled water was used for 3650 cycles (7300 strokes) for each specimen. Data were analyzed using t-test and ANOVA. A p-value of ≤ to 0.05 was considered significant. The highest mean value of surface gloss was identified in CU (stained—water) (4.3 (0.47)) (ΔE*) and EN (stained—acid) (4.3 (1.00)) (ΔE*) specimens, whereas the lowest mean value was shown by SH (stained—acid) (2.04 (0.42)) (ΔE*) samples. The highest mean value of surface roughness was observed in SH (0.40 (0.99)) Ra (stained—acid) whereas the lowest in VM (0.13 (0.039)) Ra (polished— water). A significant difference (p < 0.05) was observed in surface roughness and gloss between the materials with simulated toothbrushing, except in VM and LU, respectively. Therefore, it can be concluded that simulated toothbrushing impacts on surface roughness and gloss, irrespective of the storage medium. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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13 pages, 3722 KiB

Open AccessArticle

An Artificial Lens Capsule with a Lens Radial Stretching System Mimicking Dynamic Eye Focusing

by Huidong Wei, James S. Wolffsohn, Otavio Gomes de Oliveira and Leon N. Davies

Polymers 2021, 13(20), 3552; https://doi.org/10.3390/polym13203552 - 15 Oct 2021

Cited by 4 | Viewed by 3990

Abstract

Presbyopia is a common eye disorder among aged people which is attributed to the loss of accommodation of the crystalline lens due to the increasing stiffness. One of the potential techniques to correct presbyopia involves removing the lens substance inside the capsule and [...] Read more.

Presbyopia is a common eye disorder among aged people which is attributed to the loss of accommodation of the crystalline lens due to the increasing stiffness. One of the potential techniques to correct presbyopia involves removing the lens substance inside the capsule and replacing it with an artificial lens. The development of such devices, e.g., accommodating intraocular lenses (AIOLs), relies on the understanding of the biomechanical behaviour of the lens capsule and the essential design verification ex vivo. To mimic the eye’s dynamic focusing ability (accommodation), an artificial lens capsule (ALC), from silicone rubber accompanied by a lens radial stretching system (LRSS) was developed. The ALC was manufactured to offer a dimension and deforming behaviour replicating the human lens capsule. The LRSS was calibrated to provide a radial stretch simulating the change of diameter of capsules during accommodating process. The biomechanical function of the ALC was addressed by studying its evolution behaviour and reaction force under multiaxial stretch from the LRSS. The study highlighted the convenience of this application by performing preliminary tests on prototypes of ophthalmic devices (e.g., AIOLs) to restore accommodation. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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14 pages, 3871 KiB

Open AccessArticle

Analysis of Ionic-Exchange of Selected Elements between Novel Nano-Hydroxyapatite-Silica Added Glass Ionomer Cement and Natural Teeth

by Imran Alam Moheet, Norhayati Luddin, Ismail Ab Rahman, Sam’an Malik Masudi, Thirumulu Ponnuraj Kannan and Nik Rozainah Nik Abd Ghani

Polymers 2021, 13(20), 3504; https://doi.org/10.3390/polym13203504 - 12 Oct 2021

Cited by 6 | Viewed by 2369

Abstract

One of the foremost missions in restorative dentistry is to discover a suitable material that can substitute lost and damaged tooth structure. To this date, most of the restorative materials utilized in dentistry are bio-inert. It is predicted that the addition of nano-HA-SiO [...] Read more.

One of the foremost missions in restorative dentistry is to discover a suitable material that can substitute lost and damaged tooth structure. To this date, most of the restorative materials utilized in dentistry are bio-inert. It is predicted that the addition of nano-HA-SiO₂ to GIC matrix could produce a material with better ion-exchange between the restorative material and natural teeth. Therefore, the aim of the current study was to synthesize and investigate the transfer of specific elements (calcium, phosphorus, fluoride, silica, strontium, and alumina) between nano-hydroxyapatite-silica added GIC (nano-HA-SiO₂-GIC) and human enamel and dentine. The novel nano-hydroxyapatite-silica (nano-HA-SiO₂) was synthesized using one-pot sol-gel method and added to cGIC. Semi-quantitative energy dispersive X-ray (EDX) analysis was carried out to determine the elemental distribution of fluorine, silicon, phosphorus, calcium, strontium, and aluminum. Semi-quantitative energy dispersive X-ray (EDX) analysis was performed by collecting line-scans and dot-scans. The results of the current study seem to confirm the ionic exchange between nano-HA-SiO₂-GIC and natural teeth, leading to the conclusion that increased remineralization may be possible with nano-HA-SiO₂-GIC as compared to cGIC (Fuji IX). Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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14 pages, 5629 KiB

Open AccessArticle

Anti-Demineralization Effects of Dental Adhesive-Composites on Enamel–Root Dentin Junction

by Yu-Jung Lai, Rena Takahashi, Po-Yen Lin, Ling Kuo, Yuan Zhou, Khairul Matin, Yu-Chih Chiang, Yasushi Shimada and Junji Tagami

Polymers 2021, 13(19), 3327; https://doi.org/10.3390/polym13193327 - 29 Sep 2021

Cited by 10 | Viewed by 2604

Abstract

Oral biofilm reactor (OBR) and pH cycling (pHC) artificial caries model were employed to evaluate the anti-demineralization effects of four composite filling systems on enamel–root dentin junction. Sixty-four enamel–root dentin blocks (6 mm × 6 mm × 2 mm) each with a cylindrical [...] Read more.

Oral biofilm reactor (OBR) and pH cycling (pHC) artificial caries model were employed to evaluate the anti-demineralization effects of four composite filling systems on enamel–root dentin junction. Sixty-four enamel–root dentin blocks (6 mm × 6 mm × 2 mm) each with a cylindrical cavity were randomly assigned to the pHC and OBR group, then four subgroups (n = 8) and filled with either the Beautifil II (BEF, SPRG-filler-containing) or Estelite (EST) composite after the adhesive (either Single Bond Universal (SBU) or FL Bond II (FL, SPRG-filler-containing)). The demineralization lesions of filling interface were examined by micro-computerized tomography (μCT) and swept-source-optical coherence tomography (SS-OCT). According to the degree of interface damage, the caries lesions were sorted into four types: Type A and B (no attachment loss); Type C and D (attachment loss). EST/SBU showed the worst demineralization lesion and attachment loss (100% Type D), while BEF/FL exhibited the shallowest lesion depth (p < 0.05, 145 ± 45 μm on enamel, 275 ± 35 μm on root dentin) and no attachment loss (75% Type A and 25% Type B). Using FL adhesive alone does not effectively reduce enamel demineralization. BEF plays a leading role in acid resistance. The combination of BEF and FL showed a cumulative synergistic effect on anti-demineralization. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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11 pages, 4629 KiB

Open AccessArticle

Influence of Dental Glass Fibers and Orthopedic Mesh on the Failure Loads of Polymethyl Methacrylate Denture Base Resin

by Muhammad H. Rana, Sharaz Shaik, Mohammad S. Hameed, Samar Al-Saleh, Eman M. AlHamdan, Abdullah Alshahrani, Abdulaziz Alqahtani, Ahmed Heji Albaqawi, Fahim Vohra and Tariq Abduljabbar

Polymers 2021, 13(16), 2793; https://doi.org/10.3390/polym13162793 - 20 Aug 2021

Cited by 12 | Viewed by 2690

Abstract

The aim of the present study was to evaluate the fracture loads of polymethyl methacrylate (PMMA) complete denture bases reinforced with glass-fiber mesh and orthopedic casting tape (OCT) in comparison to conventional PMMA dentures under artificial aging. Dental fiberglass framework (Group 1) and [...] Read more.

The aim of the present study was to evaluate the fracture loads of polymethyl methacrylate (PMMA) complete denture bases reinforced with glass-fiber mesh and orthopedic casting tape (OCT) in comparison to conventional PMMA dentures under artificial aging. Dental fiberglass framework (Group 1) and OCT (Group 2 and 3) reinforced PMMA acrylic dentures were fabricated on the edentulous ridge. Ten PMMA dentures without reinforcement (Group 4) were included as controls. All specimens were placed in a chewing simulator chamber, and fatigue load was applied. To assess the fracture loads, static loads with a universal testing machine were applied. Fractured specimens in each group were evaluated under a scanning electron microscope. The data were statistically analyzed employing analysis of variance and Tukey post-hoc test. The association of denture weight and thickness on fracture load was assessed using Pearson and Spearman correlations. Dental fiberglass (Group 1) displayed the highest fracture load (692.33 ± 751.41 N), and Group 4 (control) exhibited the lowest fracture loads (281.41 ± 302.51 N). Dentures reinforced with fiberglass mesh framework exhibited intact fractures. In contrast, Group 2 and 3 specimens using OCT demonstrated ditching fractures. It was observed that the thickness and weight of all the reinforced specimens influenced the load required to fracture the dentures (p < 0.001). Denture specimens strengthened with OCT (Groups 2 and 3) exhibited failure loads lower than dental fiberglass (Group 1) specimens but higher than unreinforced controls. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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13 pages, 4771 KiB

Open AccessArticle

Influence of ER-CR-YSGG Laser and Photodynamic Therapy on the Dentin Bond Integrity of Nano-Hydroxyapatite Containing Resin Dentin Adhesive: SEM-EDX, Micro-Raman, Micro-Tensile, and FTIR Evaluation

by Abdullah S. Aljamhan, Mohammad H. Alrefeai, Alhanouf Alhabdan, Sarah A. Alhusseini, Imran Farooq, Fahim Vohra, Mustafa Naseem and Fahad Alkhudhairy

Polymers 2021, 13(12), 1903; https://doi.org/10.3390/polym13121903 - 8 Jun 2021

Cited by 31 | Viewed by 2897

Abstract

The study aimed to analyze the effect of the addition of nano-hydroxyapatite (nano-HA) particles on the mechanical properties of experimental adhesive (EA). Furthermore, dentin interaction of EA (without nano-HA) and EA with nano-HA (hereon referred to as HA-10%) were also investigated and equated. [...] Read more.

The study aimed to analyze the effect of the addition of nano-hydroxyapatite (nano-HA) particles on the mechanical properties of experimental adhesive (EA). Furthermore, dentin interaction of EA (without nano-HA) and EA with nano-HA (hereon referred to as HA-10%) were also investigated and equated. Methods consisting of scanning electron microscopy (SEM)–energy-dispersive X-ray spectroscopy (EDX), micro-Raman spectroscopy, micro-tensile bond strength (µTBS) test, and Fourier transform infrared (FTIR) spectroscopy were employed to study nano-HA particles shape, dentin bond strength, degree of conversion (DC), and adhesive–dentin interaction. Ninety teeth (N = 90) were collected, and pre-bonding, conditioning of dentin was performed utilizing phosphoric acid (H₃PO₄) etching, photodynamic therapy (PDT), and ER-CR-YSGG (ECY) laser. The teeth were set to form bonded specimens using two adhesives. Nano-HA particles were spherical-shaped, and EDX confirmed the presence of oxygen, calcium, and phosphorus. Micro-Raman spectroscopy revealed distinct phosphate and carbonate peaks for nano-HA. The µTBS test demonstrated highest values for HA-10% group on the H₃PO₄ conditioned dentin. The greatest DC was observed for the EA group. The addition of nano-HA-10 wt.% particles in dentin adhesive resulted in improved bond strength. The incorporation also demonstrated acceptable DC (although lower than EA group), suitable dentin interaction, and resin tag formation. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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18 pages, 6691 KiB

Open AccessArticle

Biofabrication of a Tubular Model of Human Urothelial Mucosa Using Human Wharton Jelly Mesenchymal Stromal Cells

by Ingrid Garzón, Boris Damián Jaimes-Parra, Manrique Pascual-Geler, José Manuel Cózar, María del Carmen Sánchez-Quevedo, María Auxiliadora Mosquera-Pacheco, Indalecio Sánchez-Montesinos, Ricardo Fernández-Valadés, Fernando Campos and Miguel Alaminos

Polymers 2021, 13(10), 1568; https://doi.org/10.3390/polym13101568 - 13 May 2021

Cited by 3 | Viewed by 2049

Abstract

Several models of bioartificial human urothelial mucosa (UM) have been described recently. In this study, we generated novel tubularized UM substitutes using alternative sources of cells. Nanostructured fibrin–agarose biomaterials containing fibroblasts isolated from the human ureter were used as stroma substitutes. Then, human [...] Read more.

Several models of bioartificial human urothelial mucosa (UM) have been described recently. In this study, we generated novel tubularized UM substitutes using alternative sources of cells. Nanostructured fibrin–agarose biomaterials containing fibroblasts isolated from the human ureter were used as stroma substitutes. Then, human Wharton jelly mesenchymal stromal cells (HWJSC) were used to generate an epithelial-like layer on top. Three differentiation media were used for 7 and 14 days. Results showed that the biofabrication methods used here succeeded in generating a tubular structure consisting of a stromal substitute with a stratified epithelial-like layer on top, especially using a medium containing epithelial growth and differentiation factors (EM), although differentiation was not complete. At the functional level, UM substitutes were able to synthesize collagen fibers, proteoglycans and glycosaminoglycans, although the levels of control UM were not reached ex vivo. Epithelial differentiation was partially achieved, especially with EM after 14 days of development, with expression of keratins 7, 8, and 13 and pancytokeratin, desmoplakin, tight-junction protein-1, and uroplakin 2, although at lower levels than controls. These results confirm the partial urothelial differentiative potential of HWJSC and suggest that the biofabrication methods explored here were able to generate a potential substitute of the human UM for future clinical use. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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Review

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15 pages, 2064 KiB

Open AccessReview

Effectiveness of Self-Assembling Peptide (P11-4) in Dental Hard Tissue Conditions: A Comprehensive Review

by Ali Azhar Dawasaz, Rafi Ahmad Togoo, Zuliani Mahmood, Ahmad Azlina and Kannan Thirumulu Ponnuraj

Polymers 2022, 14(4), 792; https://doi.org/10.3390/polym14040792 - 18 Feb 2022

Cited by 15 | Viewed by 4700

Abstract

The limitations on the use of fluoride therapy in dental caries prevention has necessitated the development of newer preventive agents. This review focusses on the recent and significant studies on P11-4 peptide with an emphasis on different applications in dental hard tissue conditions. [...] Read more.

The limitations on the use of fluoride therapy in dental caries prevention has necessitated the development of newer preventive agents. This review focusses on the recent and significant studies on P11-4 peptide with an emphasis on different applications in dental hard tissue conditions. The self-assembling peptide P11-4 diffuses into the subsurface lesion assembles into aggregates throughout the lesion, supporting the nucleation of de novo hydroxyapatite nanocrystals, resulting in increased mineral density. P11-4 treated teeth shows more remarkable changes in the lesion area between the first and second weeks. The biomimetic remineralisation facilitated in conjunction with fluoride application is an effective and non-invasive treatment for early carious lesions. Despite, some studies have reported that the P11-4 group had the least amount of remineralised enamel microhardness and a significantly lower mean calcium/phosphate weight percentage ratio than the others. In addition, when compared to a low-viscosity resin, self-assembling peptides could neither inhibit nor mask the lesions significantly. Moreover, when it is combined with other agents, better results can be achieved, allowing more effective biomimetic remineralisation. Other applications discussed include treatment of dental erosion, tooth whitening and dentinal caries. However, the evidence on its true clinical potential in varied dental diseases still remains under-explored, which calls for future cohort studies on its in vivo efficacy. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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15 pages, 7019 KiB

Open AccessReview

Synergistic Effect of Bioactive Inorganic Fillers in Enhancing Properties of Dentin Adhesives—A Review

by Imran Farooq, Saqib Ali, Samar Al-Saleh, Eman M. AlHamdan, Mohammad H. AlRefeai, Tariq Abduljabbar and Fahim Vohra

Polymers 2021, 13(13), 2169; https://doi.org/10.3390/polym13132169 - 30 Jun 2021

Cited by 33 | Viewed by 3712

Abstract

Dentin adhesives (DAs) play a critical role in the clinical success of dental resin composite (DRC) restorations. A strong bond between the adhesive and dentin improves the longevity of the restoration, but it is strongly dependent on the various properties of DAs. The [...] Read more.

Dentin adhesives (DAs) play a critical role in the clinical success of dental resin composite (DRC) restorations. A strong bond between the adhesive and dentin improves the longevity of the restoration, but it is strongly dependent on the various properties of DAs. The current review was aimed at summarizing the information present in the literature regarding the improvement of the properties of DAs noticed after the addition of bioactive inorganic fillers. From our search, we were able to find evidence of multiple bioactive inorganic fillers (bioactive glass, hydroxyapatite, amorphous calcium phosphate, graphene oxide, calcium chloride, zinc chloride, silica, and niobium pentoxide) in the literature that have been used to improve the different properties of DAs. These improvements can be seen in the form of improved hardness, higher modulus of elasticity, enhanced bond, flexural, and ultimate tensile strength, improved fracture toughness, reduced nanoleakage, remineralization of the adhesive–dentin interface, improved resin tag formation, greater radiopacity, antibacterial effect, and improved DC (observed for some fillers). Most of the studies dealing with the subject area are in vitro. Future in situ and in vivo studies are recommended to positively attest to the results of laboratory findings. Full article

(This article belongs to the Special Issue Bioactive Polymer Composites and Their Clinical Applications)

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