Search Results (104)

Background: This study developed and characterized a novel drug delivery system (DDS) for potential use in oral surgery, combining poly(lactic-co-glycolic acid) (PLGA) microspheres loaded with chlorhexidine (MS-CHX) and a polyethylene glycol (PEG)-based hydrogel containing dexketoprofen (HG-DXT). Methods: MS-CHX was synthesized using a double emulsion evaporation method, while HG-DXT was formulated from a PEG blend. The components were combined in a 2:1 ratio to create the MS-CHX/HG-DXT DDS. Characterization techniques included differential scanning calorimetry (DSC), thermogravimetric analysis (TGA), scanning electron microscopy (SEM), Fourier transform infrared spectroscopy (FTIR), and energy-dispersive X-ray spectroscopy (EDS). Antibacterial activity was evaluated using disk diffusion assays against E. faecalis, E. coli, S. aureus, and C. albicans. Biocompatibility was assessed with MTS, and drug release was measured via high-performance liquid chromatography (HPLC) in vitro. Results: CHX-loaded microspheres showed spherical morphology, stability above 37 °C, and antimicrobial efficacy. HG-DXT demonstrated good biocompatibility (80% of cell viability) and stable physicochemical properties (stability at 50-day storage). The DDS exhibited a biphasic release: an initial burst of dexketoprofen for analgesia, followed by sustained release of chlorhexidine for antimicrobial protection. Conclusions: This novel dual-action DDS showed promising characteristics and a favorable release profile, supporting its potential as a therapeutic alternative for post-operative pain and infection control in oral surgical procedures. Full article

Poor drug entrapment, burst release, and variable drug release profiles are the most critical challenges associated with biodegradable-polymer-based microspheres. In this study, biodegradable-polymer-based microspheres were used to entrap an antiplatelet drug, eptifibatide, using a single-emulsion solvent evaporation method. Critical challenges associated with biodegradable-polymer-based microspheres were addressed by incorporating different additives in the drug or polymer phase. Additives such as hydroxy propyl beta cyclodextrins (HPβCD), carboxy methyl cellulose sodium (Na CMC), and trehalose were added to the drug phase to evaluate their impact on the entrapment and stability of eptifibatide. The effect of the addition of additives such as polyvinyl alcohol (PVA), polyethylene glycol-400 (PEG-400), and methoxy polyethylene glycol phospholipid dimyristoyl phosphatidylethanolamine (mPEG-2000-DMPE, Na) to the polymer phase on the release profile of eptifibatide was evaluated. The inclusion of HPβCD resulted in good drug entrapment and helped control the initial unwanted burst release. Including Na CMC increased eptifibatide entrapment from 75% to 95%. Trehalose helped prevent the degradation of eptifibatide during lyophilization, and including PVA and PEG-400 reduced the lag phase and led to a controlled-release profile. Thus, including additives in the formulation can effectively improve the drug load and address issues associated with biodegradable-polymer-based microspheres. Full article

Long-acting injectable (LAI) formulations have revolutionized veterinary pharmaceuticals by improving patient compliance, minimizing dosage frequency, and improving therapeutic efficacy. These formulations utilize advanced drug delivery technologies, including microspheres, liposomes, oil solutions/suspensions, in situ-forming gels, and implants to achieve extended drug release. Biodegradable polymers such as poly(lactic-co-glycolic acid) (PLGA), and polycaprolactone (PCL) have been approved by the USFDA and are widely employed in the development of various LAIs, offering controlled drug release and minimizing the side effects. Various classes of veterinary medicines, including non-steroidal anti-inflammatory drugs (NSAIDs), antibiotics, and reproductive hormones, have been successfully formulated as LAIs. Some remarkable LAI products, such as ProHeart^® (moxidectin), Excede^® (ceftiofur), and POSILACTM (recombinant bovine somatotropin), show clinical relevance and commercial success. This review provides comprehensive information on the formulation strategies currently being used and the emerging technologies in LAIs for veterinary purposes. Additionally, challenges in characterization, in vitro testing, in vitro in vivo correlation (IVIVC), and safety concerns regarding biocompatibility are discussed, along with the prospects for next-generation LAIs. Continued advancement in the field of LAI in veterinary medicine is essential for improving animal health. Full article

Ulcerative colitis (UC) is a chronic inflammation disease with severe impact on quality of life, with limited treatment options. Ramulus Mori alkaloids (SZ-A) from Morus alba show promise for UC treatment due to their safety and pharmacological effects, including anti-inflammation and barrier repair. However, their clinical use has been limited by gastrointestinal flatulence as a side effect due to their pharmacological action as an α-glucosidase inhibitor targeting the small intestine following oral administration. Therefore, constructing a colon-targeted formulation to deliver SZ-A is an advantageous strategy to improve UC therapy. In this study, we used the complex formed by thiolated hyaluronic acid, which has mucosal adhesion and inflammation-targeting properties, and SZ-A as an intermediate carrier and prepared sodium alginate-modified PLGA microspheres (SZ-A@MSs) with the double emulsion method to achieve efficient encapsulation of SZ-A. Specifically, sodium alginate serves as a gastric acid protectant and microbiota-responsive material, enabling the precise and responsive release of microspheres in the colonic region. SZ-A@MSs have a particle size of about 30 µm, a drug loading of about 12.0%, and an encapsulation efficiency of about 31.7% and function through intestinal adhesion to and targeting of inflammatory sites. SZ-A@MSs showed antioxidant and anti-inflammatory abilities in Raw264.7 cells. In vivo imaging results suggest that SZ-A@MSs have good colon site retention and sustained-release effect. Pharmacodynamic results show that SZ-A@MSs display good efficacy, including the ability to inhibit weight loss, inhibit colonic atrophy, and inhibit the secretion of inflammatory factors. In conclusion, SZ-A@MSs have good colon-targeting properties, can improve therapeutic effects, and provide a potential treatment method for UC. Full article

Chronic wound infections present a persistent medical challenge; however, advancements in wound dressings and antimicrobial nanomaterials offer promising solutions for improving healing outcomes. This study introduces a hydrothermal synthesis approach for producing zinc oxide (ZnO) and copper oxide (CuO) nanoparticles, subsequently incorporated into PLGA microspheres and embedded within collagen hydrogels. The nanoparticles’ physicochemical properties were characterized using X-ray diffraction (XRD) to confirm crystalline structure, scanning electron microscopy (SEM) for surface morphology, and Fourier-transform infrared spectroscopy (FT-IR) to verify functional groups and successful hydrogel integration. The hydrogels were tested for antimicrobial activity against Staphylococcus aureus, Pseudomonas aeruginosa, and Candida albicans, which are key pathogens in chronic wounds. Biocompatibility was assessed using the human HaCat keratinocyte cell line. Both ZnO- and CuO-loaded hydrogels exhibited broad-spectrum antimicrobial efficacy. Cytocompatibility tests demonstrated that both ZnO- and CuO-loaded hydrogels sustain cell viability and proliferation, highlighting their biocompatibility and suitability for chronic wound healing applications, with superior biological performance of ZnO-loaded hydrogels. Furthermore, the distinct antimicrobial profiles of ZnO and CuO hydrogels suggest their tailored use based on wound microbial composition, with CuO hydrogels excelling in antibacterial applications and ZnO hydrogels showing potential for antifungal treatments. These results underscore the potential of nanoparticle-based collagen hydrogels as innovative therapeutic tools for managing chronic wounds. Full article

Polymer-based drug-controlled release systems offer greater efficacy and potency than conventional therapies. However, prominent drug side effects, lower circulation, and low drug loading capabilities limit their application range. In this work, the combination of Simvastatin (SIV) and Carvacrol (CAV) into PEG-PLGA microspheres (SIV-CAV-PP-MS) was achieved via an emulsification-solvent evaporation technique, resulting in microspheres characterized by high encapsulation efficiency and reduced particle size. In vitro studies demonstrated that the cumulative drug release increased with higher SIV and CAV levels in the release medium, reaching 88.91% and 89.35% at 25 days. Pharmacokinetic analysis revealed that the concentrations of SIV and CAV reached their maximum levels at approximately seven days in the SIV-CAV-PP-MS group, which indicates that using PEG-PLGA as a carrier significantly delays drug release. In vivo, evaluation demonstrated that the SIV-CAV-PP-MS high-dose group and positive drug control group showed reductions in low-density lipoprotein cholesterol levels by 0.39-fold and 0.36-fold compared to the Hyperlipidemia model group, and the addition of CAV significantly enhanced the lipid-lowering effects of SIV. Histological examinations indicated that the SIV-CAV-PP-MS medium-dose group displayed histological features more closely resembling those of normal mice compared to the Simvastatin control group, with a well-organized hepatocyte structure, a significant reduction in lipids, and improved liver health. The prepared polymeric microsphere utilizing SIV and SAV will be a promising dosage form for hyperlipidemia disease patients, with superior lipid-lowering efficacy and improved patient compliance. Full article

The present study evaluates the effect of PEG content on the characteristics of poly(lactic-co-glycolic acid)-polyoxyethylene (PLGA-PEG) microspheres loaded with a small molecular weight drug on the polymer matrix degradation behavior of the polymeric matrix and drug release profile. Aclacinomycin A (ACM) was encapsulated in PLGA-PEG microspheres with varying PEG content (0%, 5%, 10%, or 15%) using the oil-in-water solvent evaporation method. Microspheres were obtained with sizes ranging from 45–70 mm, drug loading around 1.3% and encapsulation efficiencies between 48–70%. The produced microspheres were further characterized in terms of degradation behavior and drug release kinetics. The results showed that while PEG content had minimal impact on drug loading and microsphere size, it significantly influenced the degradation behavior of the microspheres and its weight in the release process. In vitro drug release profiles exhibited a three-phase pattern for all PLGA-PEG microspheres with faster and more extensive ACM release compared to PLGA microspheres, being the release improved with the PEG content increase. The Corrigan model was successfully applied to the release data yielding burst-phase kinetic constants (k_b) between 0.082–0.288 and degradation/erosion kinetic constants (k) between 0.054–0.093 day⁻¹, both of which increased with higher PEG content. Full article

The aim of this study was to develop a long-acting injectable formulation of risperidone using polylactic acid (PLA) or poly (lactic-co-glycolic acid) (PLGA), a biodegradable and biocompatible polymer. Risperidone microspheres (RMs) were prepared by creating an O/W emulsion using dichloromethane (DCM) as a solvent and then employing the solvent evaporation method. The RMs were prepared with four different risperidone-to-PLGA ratios (1:1, 1:1.3, 1:2, and 1:3 (w/w)), and each ratio was subjected to the same manufacturing process. The physicochemical properties of the prepared RMs, such as their shape, particle size, drug loading ratio, encapsulation efficiency, and in vitro degradation profile, were evaluated. The particle size of the RMs ranged from 30 to 100 μm, with larger PLGA ratios resulting in larger RM sizes. The drug loading ratio was inversely proportional to the increase in the PLGA ratio in the RMs, and all the formulations showed improved release profiles compared to the reference drug, Risperdal Consta^®. The release data modeling results showed that the RM-3 formulation with a 1:1 (w/w) ratio of risperidone and PLGA exhibited a release pattern close to zero-order kinetics. The manufactured RMs were confirmed to have the potential to be used as a long-acting risperidone injection with sustained and stable release as well as an extended dosing interval. Full article

Swine Glasser’s disease, instigated by Haemophilus parasuis (H. parasuis), is a significant bacterial infection that causes substantial economic losses in pig farming operations. The role of mucosal immunity is pivotal in defending against H. parasuis. This study focused on the construction of PLGA microspheres that encapsulate the outer membrane protein OMP16 from H. parasuis (PLGA-OMP16) and evaluated their immunological effectiveness in a mouse model. After being intranasally immunized twice, the PLGA-OMP16 microspheres effectively induced IgAs in saliva and nasal and lung fluids. The PLGA-OMP16 microspheres also significantly increased the number of anti H. parasuis IgGs in serum. Furthermore, the PLGA-OMP16 microspheres triggered elevated levels of IL-2, IL-4, and IFN-γ. The mice vaccinated with PLGA-OMP16 showed a significant reduction in H. parasuis burden in the spleen and lungs following bacterial challenge. These results indicate that intranasal immunization using PLGA microspheres is a promising adjuvant delivery system for vaccines targeting H. parasuis. Full article

Poly(lactic-co-glycolic acid) (PLGA) is a widely used biodegradable and biocompatible copolymer in drug delivery systems (DDSs). In this article, we highlight the critical physicochemical properties of PLGA, including its molecular weight, intrinsic viscosity, monomer ratio, blockiness, and end caps, that significantly influence drug release profiles and degradation times. This review also covers the extensive literature on the application of PLGA in delivering small-molecule drugs, proteins, peptides, antibiotics, and antiviral drugs. Furthermore, we discuss the role of PLGA-based DDSs in the treating various diseases, including cancer, neurological disorders, pain, and inflammation. The incorporation of drugs into PLGA nanoparticles and microspheres has been shown to enhance their therapeutic efficacy, reduce toxicity, and improve patient compliance. Overall, PLGA-based DDSs holds great promise for the advancement of the treatment and management of multiple chronic conditions. Full article

Biomaterials play an important role in treating bone defects. The functional characteristics of scaffolds, such as their structure, mechanical strength, and antibacterial and osteogenesis activities, effectively promote bone regeneration. In this study, mineralized collagen and polycaprolactone were used to prepare loaded porous scaffolds with bilayer-structured microspheres with dual antibacterial and osteogenesis functions. The different drug release mechanisms of PLGA and chitosan in PLGA/CS microspheres caused differences in the drug release models in terms of the duration and rate of Pac-525 and BMP-2 release. The prepared PLGA_(BMP-2)/CS_(Pac-525)@MC/PCL scaffolds were analyzed in terms of physical characteristics, bioactivity, and antibacterial properties. The scaffolds with a dimensional porous structure showed similar porosity and pore diameter to cancellous bone. The release curve of the microspheres and scaffolds with high encapsulation rates displayed the two-stage release of Pac-525 and BMP-2 over 30 days. It was found that the scaffolds could inhibit S. aureus and E. coli and then promote ALP activity. The PLGA_(BMP-2)/CS_(Pac-525)@MC/PCL scaffold could be used as a dual delivery system to promote bone regeneration. Full article

Accurately measuring drug and its release kinetics in both in vitro and in vivo environments is crucial for enhancing therapeutic effectiveness while minimizing potential side effects. Nevertheless, the real-time visualization of drug release from microspheres to monitor potential overdoses remains a challenge. The primary objective of this investigation was to employ fluorescence imaging for the real-time monitoring of drug release from microspheres in vitro, thereby simplifying the laborious analysis associated with the detection of drug release. Two distinct varieties of microspheres were fabricated, each encapsulating different drugs within PLGA polymers. Cy5 was selected as the donor, and Cy7 was selected as the acceptor for visualization and quantification of the facilitated microsphere drug release through the application of the fluorescence resonance energy transfer (FRET) principle. The findings from the in vitro experiments indicate a correlation between the FRET fluorescence alterations and the drug release profiles of the microspheres. Full article

Osteoporosis is the most common metabolic bone disorder and is characterized by decreased bone density, which has a relationship with the quality of life among the aging population. Previous research has found that activation of the dopamine D1 receptor can improve bone mass formation. SKF38393 is an agonist of dopamine D1 receptors. However, as a small-molecule drug, SKF38393 is unstable and releases quickly. The aim of this study was to prototype polylactic-co-glycolic acid (PLGA)/SKF38393 microspheres and assess their potential osteogenic effects compared to those under the free administration of SKF38393. The cytocompatibility of PLGA/SKF38393 was determined via CCK-8 and live/dead cell staining; the osteogenic effects in vitro were determined with ALP and alizarin red staining, qRT-PCR, and Western blotting; and the in vivo effects were assessed using 25 Balb/c mice. We also used a PCR array to explore the possible signaling pathway changes after employing PLGA/SKF38393. Our experiments demonstrated that the osteogenic effect of D1Rs activated by the PLGA/SKF38393 microsphere was better than that under free administration, both in vitro and in vivo. According to the PCR array, this result might be associated with six signaling pathways (graphical abstract). Ultimately, in this study, we prototyped PLGA/SKF38393, demonstrated its effectiveness, and preliminarily analyzed its mechanism of action. Full article

In situ depot gel is a type of polymeric long-acting injectable (pLAI) drug delivery system; compared to microsphere technology, its preparation process is simpler and more conducive to industrialization. To ensure the chemical stability of peptide ACTY116, we avoided the use of harsh conditions such as high temperatures, high shear mixing, or homogenization; maintaining a water-free and oxygen-free environment was also critical to prevent hydrolysis and oxidation. Molecular dynamics (MDs) simulations were employed to assess the stability mechanism between ACTY116 and the pLAI system. The initial structure of ACTY116 with an alpha helix conformation was constructed using SYBYL-X, and the copolymer PLGA was generated by AMBER 16; results showed that PLGA-based in situ depot gel improved conformational stability of ACTY116 through hydrogen bonds formed between peptide ACTY116 and the components of the pLAI formulation, while PLGA (Poly(DL-lactide-co-glycolide)) also created steric hindrance and shielding effects to prevent conformational changes. As a result, the chemical and conformational stability and in vivo long-acting characteristics of ACTY116 ensure its enhanced efficacy. In summary, we successfully achieved our objective of developing a highly stable peptide-loaded long-acting injectable (LAI) in situ depot gel formulation that is stable for at least 3 months under harsh conditions (40 °C, above body temperature), elucidating the underlying stabilisation mechanism, and the high stability of the ACTY116 pLAI formulation creates favourable conditions for its in vivo pharmacological activity lasting for weeks or even months. Full article

For many years, sustained-release drug delivery systems (SRDDS) have emerged as a featured topic in the pharmaceutical field. Particularly for chronic diseases, such as osteoarthritis, there is a lot of demand for SRDDS because of the long treatment period and repetitive medication administration. Thus, we developed an injectable PLGA-F127 microsphere (MS) that is capable of the in situ conversion to an implant. The microprecipitation method for PLGA-F127 MS was established, and the physicochemical stability of the products was confirmed. The microspheres were assembled into a single mass in 37 °C aqueous conditions and showed a remarkably delayed drug release profile. First, the release started with no significant initial burst and lagged for 60 days. After that, in the next 40 days, the remaining 75% of the drugs were constantly released until day 105. We expect that our PLGA-F127 MS could be employed to extend the release period of 2 months of medication to 4 months. This could be a valuable solution for developing novel SRDDS for local injections. Full article