Cell colonization of synthetic polymers can be regulated by physical and chemical modifications of the polymer surface. High-density and low-density polyethylene (HDPE and LDPE) were therefore activated with Ar⁺ plasma and grafted with fibronectin (Fn) or bovine serum albumin (BSA). The water drop contact angle usually decreased on the plasma-treated samples, due to the formation of oxidized groups, and this decrease was inversely related to the plasma exposure time (50–300 s). The presence of nitrogen and sulfur on the polymer surface, revealed by X-ray photoelectron spectroscopy (XPS), and also by immunofluorescence staining, showed that Fn and BSA were bound to this surface, particularly to HDPE. Plasma modification and grafting with Fn and BSA increased the nanoscale surface roughness of the polymer. This was mainly manifested on HDPE. Plasma treatment and grafting with Fn or BSA improved the adhesion and growth of vascular smooth muscle cells in a serum-supplemented medium. The final cell population densities on day 6 after seeding were on an average higher on LDPE than on HDPE. In a serum-free medium, BSA grafted to the polymer surface hampered cell adhesion. Thus, the cell behavior on polyethylene can be modulated by its type, intensity of plasma modification, grafting with biomolecules, and composition of the culture medium. Full article

An ultrasensitive portable electrochemical immunosensor for human immunodeficiency virus p24 (HIV p24) antigen detection has been developed, whereby the detection sensitivity was 1000 times higher than that of the ELISA method. Firstly, a novel HRP enzyme–antibody copolymer (EV-p24 Ab2) was synthesized through an EnVision regent (EV, a dextrin amine skeleton anchoring more than 100 molecules of HRP and 15 molecules of anti IgG), then incubated in the secondary antibody of p24. Secondly, the copolymer was immobilized on the gold nanocolloids (AuNPs) to fabricate a novel signal tag (AuNPs/EV-p24 Ab2). Subsequently, a sandwich-type immunoreaction would take place between the capture probe (silicon dioxide-coated magnetic Fe₃O₄ nanoparticles (MNPs) labeled with the primary p24 antibody (MNPs-p24 Ab1)), p24 (different concentrations) and the signal tag [AuNPs/EV-p24 Ab2)] to form the immunocomplex. Finally, the immunocomplex was absorbed on the surface of screen printed carbon electrode (SPCE) by a magnet and immersed in the o-hydroxyl phenol (HQ) and H₂O₂. The large amounts of HRP on the signal tag can catalyze the oxidation of HQ by H₂O₂, which can induce an amplified reductive current. Moreover, the capture probe could improve the accumulation ability of p24 and facilitate its separation from the substrate through the magnet. Under optimal conditions, the proposed immunoassay exhibited good sensitivity to p24 within a certain concentration range from 0.001 to 10.00 ng/mL, with a detection limit of 0.5 pg/mL (S/N = 3). The proposed method can be used for real-time and early detection of HIV-infected people. Full article

The objective of this work was to examine the potential of oscillating nanomagnetic gene transfection systems (magnefect-nano™) for improving the transfection efficiency of NIH3T3 mouse embryonic fibroblasts (MEFs) in comparison to other non-viral transfection techniques—static magnetofection™ and the cationic lipid agent, Lipofectamine 2000™. Magnetic nanoparticles (MNPs) associated with the plasmid coding for green fluorescent protein (GFP) were used to transfect NIH3T3 cells. The magnefect-nano system was evaluated for transfection efficiency, and any potential associated effects on cell viability were investigated. MNPs associated with the plasmid coding for GFP were efficiently delivered into NIH3T3 cells, and the magnefect-nano system significantly enhanced overall transfection efficiency in comparison to lipid-mediated gene delivery. MNP dosage used in this work was not found to affect the cell viability and/or morphology of the cells. Non-viral transfection using MNPs and the magnefect-nano system can be used to transfect NIH3T3 cells and direct reporter gene delivery, highlighting the wide potential of nanomagnetic gene transfection in gene therapy. Full article

Fish gelatin (FG) extracted from sea bream scales was reacted with glycidyl methacrylate (GMA), and the product (FG-GMA) was used for photopolymerization using a radical photoinitiator in the presence or absence of imogolite nanofibers in the aqueous solution. The synthesis of FG-GMA was confirmed by ¹H NMR spectroscopy, and photopolymerization of FG-GMA was achieved successfully by irradiation with ultraviolet (UV) light for 3 min to yield translucent composite hydrogels. The concentration of FG-GMA varied from 10% to 30% without imogolite, and that of imogolite varied from 0% to 2.0%. A microtomed gel sample was observed with a transmission electron microscope (TEM), and imogolite nanofibers were found to be dispersed finely in the gelatin matrix. Scanning electron microscope (SEM) observation of the lyophilized gel revealed that it had a porous morphology. Mechanical properties of hydrogels were measured by compression tests using a mechanical tester, and viscoelastic properties were measured using a rheometer. The mechanical strength and storage modulus of the hydrogel increased with an increase of imogolite. Full article

Vinorelbine tartrate (VLBT), as a kind of high hydrophilic and temperature-induced degradation drug, was prepared into nanoparticles by a desolvation procedure. Bovine serum albumin (BSA), as a drug carrier, was stabilized by chemical cross-linking with glutaraldehyde. Firstly, the optimization process of preparing VLBT-loaded BSA nanoparticles (VLBT-BSANPs) was accomplished using response surface methodology (RSM) by desolvation. Then VLBT-BSANPs were conjugated with folate, namely Fa-BSANPs-VLBT. Hence targeting drug carrier delivery system loading VLBT was produced. In this study, the characteristics of the nanoparticles, such as the amount of folate conjugation, surface morphology, surface chemistry, physical status of VLBT in Fa-BSANPs-VLBT, stability of Fa-BSANPs-VLBT with mannitol and in vitro drug release behavior were all investigated. The VLBT-BSANPs were obtained under optimum conditions, with a mean particle size (MPS) of 155.4 nm and a zeta potential (ZP) of −32.97 mV at a pH value of 5.4. Drug loading efficiency (DLE) and drug entrapment efficiency (DEE) of this obtained drug were approximately 45.6% and 90.6%, respectively. Full article

The supercritical CO₂-based technologies have been widely used in the formation of drug and/or polymer particles for biomedical applications. In this study, nanoparticles of poly-(methyl vinyl ether-co-maleic anhydride) (PVM/MA) were successfully fabricated by a process of solution-enhanced dispersion by supercritical CO₂ (SEDS). A 2³ factorial experiment was designed to investigate and identify the significance of the processing parameters (concentration, flow and solvent/nonsolvent) for the surface morphology, particle size, and particle size distribution of the products. The effect of the concentration of PVM/MA was found to be dominant in the results regarding particle size. Decreasing the initial solution concentration of PVM/MA decreased the particle size significantly. After optimization, the resulting PVM/MA nanoparticles exhibited a good spherical shape, a smooth surface, and a narrow particle size distribution. Fourier transform infrared spectroscopy (FTIR) spectra demonstrated that the chemical composition of PVM/MA was not altered during the SEDS process and that the SEDS process was therefore a typical physical process. The absolute value of zeta potential of the obtained PVM/MA nanoparticles was larger than 40 mV, indicating the samples’ stability in aqueous suspension. Analysis of thermogravimetry-differential scanning calorimetry (TG-DSC) revealed that the effect of the SEDS process on the thermostability of PVM/MA was negligible. The results of gas chromatography (GC) analysis confirmed that the SEDS process could efficiently remove the organic residue. Full article

Nanotechnologists have become involved in regenerative medicine via creation of biomaterials and nanostructures with potential clinical implications. Their aim is to develop systems that can mimic, reinforce or even create in vivo tissue repair strategies. In fact, in the last decade, important advances in the field of tissue engineering, cell therapy and cell delivery have already been achieved. In this review, we will delve into the latest research advances and discuss whether cell and/or tissue repair devices are a possibility. Focusing on the application of nanotechnology in tissue engineering research, this review highlights recent advances in the application of nano-engineered scaffolds designed to replace or restore the followed tissues: (i) skin; (ii) cartilage; (iii) bone; (iv) nerve; and (v) cardiac. Full article