CULTURED HAIR FOLLICLE CELLS FOR THE TREATMENT OF VITILIGO

Objective: The objective of this study was to develop a method to isolate cells from hair follicles and cultured them in a hydrogel.Methods: Different cell types obtained from hair follicles were investigated and mixed with three formulations of Lutrol® F-127-based hydrogels. The percentages of the cell attachment and viability were observed within 48 h.Results: The results showed that three cell types, including keratinocyte, dermal papilla, and melanocyte cells, were obtained, as shown by the expression of their corresponding genes. All formulations of the hydrogels supported cell attachment and viability. Interestingly, more than 60% cell attachment and viability were found in lutrol hydrogels supplemented with either fetal bovine serum (FBS) or heat-activated human serum.Conclusion: Higher cell attachment and viability were observed when the hair follicle cells were cultured in the hydrogel with FBS than the hydrogel with human serum. However, the lutrol gel formulation with human serum was more appropriate to be used in the future clinical study, as this formulation contained no animal-derived component

Controlled Release Mechanism of Vancomycin from Double-Layer Poly-<span style="font-variant: small-caps">L</span>-Lactic Acid-Coated Implants for Prevention of Bacterial Infection

Implantation failure due to bacterial infection incurs significant medical expenditure annually, and treatment tends to be complicated. This study proposes a method to prevent bacterial infection in implants using an antibiotic delivery system consisting of vancomycin loaded into poly-L-lactic acid (PLLA) matrices. A thin layer of this antibiotic-containing polymer was formed on stainless steel surfaces using a simple dip-coating method. SEM images of the polymeric layer revealed a honeycomb structure of the PLLA network with the entrapment of vancomycin molecules inside. In the in vitro release study, a rapid burst release was observed, followed by a sustained release of vancomycin for approximately 3 days. To extend the release time, a drug-free topcoat of PLLA was introduced to provide a diffusion resistance layer. As expected, the formulation with the drug-free topcoat exhibited a significant extension of the release time to approximately three weeks. Furthermore, the bonding strength between the double-layer polymer and the stainless steel substrate, which was an important property reflecting the quality of the coating, significantly increased compared to that of the single layer to the level that met the requirement for medical coating applications. The release profile of vancomycin from the double-layer PLLA film was best fitted with the Korsmeyer–Peppas model, indicating a combination of Fickian diffusion-controlled release and a polymer relaxation mechanism. More importantly, the double-layer vancomycin-PLLA coating exhibited antibacterial activity against S. aureus, as confirmed by the agar diffusion assay, the bacterial survival assay, and the inhibition of bacterial surface colonization without being toxic to normal cells (L929). Our results showed that the proposed antibiotic delivery system using the double-layer PLLA coating is a promising solution to prevent bacterial infection that may occur after orthopedic implantation

Preparation of Folate-Conjugated Pluronic F127/Chitosan Core-Shell Nanoparticles Encapsulating Doxorubicin for Breast Cancer Treatment

A targeting drug delivery system using folate-conjugated pluronic F127/chitosan core-shell nanoparticles was developed to deliver doxorubicin (DOX) to the target cancer cells. First, DOX was encapsulated in pluronic F127 micelle cores in the presence of sodium dodecyl sulfate (SDS) by a self-assembly method. To form a shell, a layer of either chitosan or folate-conjugated chitosan was deposited onto the pluronic micelles. The encapsulation efficiency was approximately 58.1±4.7%. The average size of the core-shell nanoparticles was 37.4±2.0 nm, while the zeta potential was 12.9±2.3 mV, indicating the presence of a shell layer and more stable particles. In an in vitro DOX release study, an initial burst release, followed by a sustained release, was observed within 24 hours. In addition, the core-shell nanoparticles showed greater cytotoxicity towards MCF-7 cells than free DOX, suggesting a better therapeutic efficacy in treating cancer

DEVELOPMENT OF A TOPICAL GEL CONTAINING A DIPEPTIDYL PEPTIDASE-4 INHIBITOR FOR WOUND HEALING APPLICATIONS: 16th August 2022; 11th January 2023; 22nd February 2023; 06th March 2023

Chronic wounds are challenging for healthcare because they are difficult to treat and cannot heal by themselves. Active compounds that can accelerate wound healing are, therefore, necessary. Dipeptidyl peptidase (DPP)-4 inhibitors are antihyperglycemic drugs widely used in patients with type 2 diabetes that not only maintain the homeostasis of blood sugar levels but have also been shown to promote chronic wound healing. In this study, we formulated a topical gel containing, sitagliptin, a commonly used DPP-4 inhibitor drug to treat diabetes, using Carbopol 940 as a base due to its high viscosity and biocompatibility. The characteristics of the sitagliptin gel, including its physical appearance, viscoelastic properties, swelling and degradation, and stability, were investigated. The gel appeared to be transparent with a uniform distribution of drug molecules and was stable at 4 °C for more than 1 month. Moreover, the gel was shown to exhibit shear thinning pseudoplastic behavior, which is desirable for topical gels. The gel could absorb up to 250% of liquid within 2 days but later degraded in aqueous solution following zeroth-order kinetics. In the in vitro release study, the cumulative release data were best fitted with the first order kinetic model, in which the release rate depended on the concentration. To further demonstrate the use of the DPP-4 inhibitor gel, the gel was applied directly onto subcutaneous wounds on experimental pigs. The topical gel was shown to exhibit the desired spread ability without causing any inflammation around the wound area which was comparable to IntraSite® gel and commercial silver nanoparticle cream

Maintenance of human chondrogenic phenotype on a dendrimer-immobilized surface for an application of cell sheet engineering

Abstract Background Dedifferentiation of chondrocytes during cell expansion is one of the barriers in tissue construction for cartilage repair. To understand chondrocyte behavior and improve cell expansion in monolayer culture, this study investigated the effects of morphological changes and cellular aggregation on the maintenance of chondrogenic capacity by observing the expression patterns of chondrogenic (collagen type II and aggrecan) and dedifferentiation (collagen type I) markers. Primary human chondrocytes were cultured on either a polystyrene surface (PS) or a polyamidoamine dendrimer surface with a fifth-generation (G5) dendron structure to create a one-step process of cell expansion and the maintenance of chondrogenic activities prior to the construction of cell sheets. Results During the first two passages (P0 - P2), the relative mRNA level of collagen type II decreased in all cultures, while that of collagen type I increased. Remarkably, the level of collagen type II was higher and aggrecan was retained in the chondrocytes, forming cell aggregates and showing some round-shaped cells with less production of stress fibers on the G5 surface compared to fibroblast-like chondrocytes with abundant stress fibers on the PS surface. The numbers of P2 chondrocytes on the G5 and PS surfaces were nearly the same and sufficient for construction of chondrocyte sheets using a temperature-responsive plate. Without a supporting material during cell sheet manipulation, chondrocyte sheets spontaneously detached and exhibited a honeycomb-like structure of stress fibers. Unlike the chondrocyte sheets constructed from cells on the PS surface, the chondrocyte sheets from cells on the G5 surface had higher chondrogenic activities, as evidenced by the high expression of chondrogenic markers and the low expression of dedifferentiation markers. Conclusions The one-step process of cell expansion and maintenance of chondrogenic activity could be obtained using the G5 surface. Human chondrocyte sheets were successfully constructed with high chondrogenic activity. These findings may lead to an alternative cultivation technique for human chondrocytes that offers high clinical potential in autologous chondrocyte implantation

Additional file 1: of Maintenance of human chondrogenic phenotype on a dendrimer-immobilized surface for an application of cell sheet engineering

Schematic illustrations showing the possible signals involved in the one-step process of expansion and differentiation for human chondrocytes on either the G5 or PS surface for chondrocyte sheet construction. (TIFF 20776 kb