We prepared porous poly(ε-caprolactone)/poly(lactic-co-glycolic acid) (PCL/PLGA) 3D scaffolds with surfaces that were modified through the co-precipitation of calcium phosphate (CAP) with binary drug components, including risedronate (RSD) and hyaluronic acid (HyA). The 3D porous biodegradable PCL/PLGA scaffolds were fabricated by sintering microspheres prepared with a 30/70 PCL/PLGA blend. The co-precipitation of the CAP coating with binary drug components significantly enhanced the proliferation and differentiation of rat mesenchymal stem cells (rMSCs) on the scaffolds. Although the presence of both HyA and RSD positively improved proliferation and differentiation, HyA and RSD were more effective on osteoblastic proliferation and differentiation, respectively. These results strongly demonstrate that the drug effects on osteoblastic responses were closely interconnected. The two drugs affect rMSCs behavior in a concentration-dependent manner, requiring a balance between proliferation and differentiation for optimal bone regeneration. We expect this surface modification technique could potentially be utilized for the fabrication of functionalized biodegradable scaffolds and delivery of drug mixtures.

This study investigates the development of risedronate (RSD)-incorporated polycaprolactone (PCL)/chitosan composite films for potential use in drug delivery systems aimed at bone repair. PCL and chitosan were blended in varying ratios (25 %, 50 %, 75 % PCL), and their miscibility, morphology, and hydrophilicity were analyzed. The effects of incorporating RSD at different concentrations (10-7 to 10-4 M) on MG63 preosteoblast cell proliferation and differentiation were also evaluated. The results demonstrated that blending of the hydrophobic PCL with hydrophilic chitosan was challenging, due to poor miscibility and phase separation. Optimal blending conditions and drying temperatures were essential for homogeneous film formation. The incorporation of RSD influenced cellular behavior, with 50 % PCL showing the most effective cell proliferation and moderate hydrophilicity. However, higher RSD concentrations (10-4 M) inhibited proliferation, while lower concentrations (10-7 M) promoted it. RSD also enhanced osteoblast differentiation, as evidenced by increased alkaline phosphatase (ALP) activity, particularly in 75 % PCL films. These findings suggest that adjusting the PCL/chitosan ratio and RSD concentration can optimize drug release and cellular responses, making this composite system a promising candidate for bone tissue engineering applications.

In order to develop catechin patches for skin regeneration at wound sites, patches with varying concentrations of catechin and chitosan were manufactured. An optimal composition ratio was determined by adjusting the drug release rate and amount, to maximize efficiency. The catechin used in this study was extracted from green tea leaves using a solvent/ultrasonication method, and its characteristics were confirmed through Fourier transform-infrared spectroscopy (FT-IR) and high-performance liquid chromatography (HPLC) analyses. Patches were prepared with different concentrations of catechin and chitosan, and various properties were analyzed using techniques such as FT-IR, water contact angle analysis, and UV-Vis spectroscopy. It was observed that as the chitosan concentration increased, the release of catechin slowed down or almost ceased. A patch manufactured with 1.5 mg/cm2 of catechin at a 1 % chitosan concentration exhibited a high initial release rate over 24 h and demonstrated cellular biocompatibility. Consequently, these patches, with tailored release characteristics based on the concentrations of chitosan and catechin, hold promise for use as drug delivery systems in wound healing applications.