Effect of Solvent on Drug Release and a Spray-Coated Matrix of a Sirolimus-Eluting Stent Coated with Poly(lactic-<i>co</i>-glycolic acid)

Sirolimus (SRL) release from the biodegradable poly­(l-lactic-<i>co</i>-glycolic acid) (PLGA) matrix was investigated for the application of drug-eluting stents (DES). In particular, this study focused on whether various organic solvents affect the interaction between SRL and PLGA and the formation of microstructures during ultrasonic coating. The SRL-loaded PLGA coated by tetrahydrofuran or acetone showed a significant initial burst, whereas that from acetonitrile was constantly released during a period of 21 days. On the basis of these results, the interactions at the molecular level of SRL with the polymer matrix were estimated according to various organic solvents. Although the topographies of the coated surface were obviously different, the correlation between surface roughness and SRL release was very poor. Irrespective of organic solvents, FT-IR data showed significantly weak SRL-PLGA interactions. From the result of wide-angle X-ray diffraction, it was confirmed that SRL was dispersed in an amorphous state in the polymer matrix after ultrasonic coating. The glass-transition temperature was also influenced by organic solvents, resulting in a plasticizing effect. The particle size of SRL appeared to determine the release profile from the PLGA matrix, which was the combination of diffusion and polymer degradation at an SRL size of more than 800 nm and the Fickian release at that of less than 300 nm. Therefore, organic solvents can lead to a heterogeneous microstructure in the SRL-loaded PLGA matrix, which is at or near the surface, consisting of aggregated drug- and polymer-rich regions. It is expected that the drug release can be controlled by physicochemical properties of organic solvents, and this study can be used effectively for localized drug release in biomedical devices such as drug-eluting stents

Additional file 1 of Multiple treatments with human embryonic stem cell-derived mesenchymal progenitor cells preserved the fertility and ovarian function of perimenopausal mice undergoing natural aging

Supplementary Material 1: Fig. 1. Impact of hESC-MPCs on MDSCs expansion in an in vitro system. (A) Representative FACS plot of MDSCs isolated from the spleen. (B) MDSC cell numbers after co-culture with hESC-MPCs. (*p < 0.05)

Mussel-Mimetic Protein-Based Adhesive Hydrogel

Hydrogel systems based on cross-linked polymeric materials which could provide both adhesion and cohesion in wet environment have been considered as a promising formulation of tissue adhesives. Inspired by marine mussel adhesion, many researchers have tried to exploit the 3,4-dihydroxyphenylalanine (DOPA) molecule as a cross-linking mediator of synthetic polymer-based hydrogels which is known to be able to achieve cohesive hardening as well as adhesive bonding with diverse surfaces. Beside DOPA residue, composition of other amino acid residues and structure of mussel adhesive proteins (MAPs) have also been considered important elements for mussel adhesion. Herein, we represent a novel protein-based hydrogel system using DOPA-containing recombinant MAP. Gelation can be achieved using both oxdiation-induced DOPA quinone-mediated covalent and Fe³⁺-mediated coordinative noncovalent cross-linking. Fe³⁺-mediated hydrogels show deformable and self-healing viscoelastic behavior in rheological analysis, which is also well-reflected in bulk adhesion strength measurement. Quinone-mediated hydrogel has higher cohesive strength and can provide sufficient gelation time for easier handling. Collectively, our newly developed MAP hydrogel can potentially be used as tissue adhesive and sealant for future applications

Biomimetic Porous PLGA Scaffolds Incorporating Decellularized Extracellular Matrix for Kidney Tissue Regeneration

Chronic kidney disease is now recognized as a major health problem, but current therapies including dialysis and renal replacement have many limitations. Consequently, biodegradable scaffolds to help repairing injured tissue are emerging as a promising approach in the field of kidney tissue engineering. Poly­(lactic-<i>co</i>-glycolic acid) (PLGA) is a useful biomedical material, but its insufficient biocompatibility caused a reduction in cell behavior and function. In this work, we developed the kidney-derived extracellular matrix (ECM) incorporated PLGA scaffolds as a cell supporting material for kidney tissue regeneration. Biomimetic PLGA scaffolds (PLGA/ECM) with different ECM concentrations were prepared by an ice particle leaching method, and their physicochemical and mechanical properties were characterized through various analyses. The proliferation of renal cortical epithelial cells on the PLGA/ECM scaffolds increased with an increase in ECM concentrations (0.2, 1, 5, and 10%) in scaffolds. The PLGA scaffold containing 10% of ECM has been shown to be an effective matrix for the repair and reconstitution of glomerulus and blood vessels in partially nephrectomized mice in vivo, compared with only PLGA control. These results suggest that not only can the tissue-engineering techniques be an effective alternative method for treatment of kidney diseases, but also the ECM incorporated PLGA scaffolds could be promising materials for biomedical applications including tissue engineered scaffolds and biodegradable implants

sj-tif-2-tej-10.1177_20417314231226105 – Supplemental material for Therapeutic potential of luteolin-loaded poly(lactic-co-glycolic acid)/modified magnesium hydroxide microsphere in functional thermosensitive hydrogel for treating neuropathic pain

Supplemental material, sj-tif-2-tej-10.1177_20417314231226105 for Therapeutic potential of luteolin-loaded poly(lactic-co-glycolic acid)/modified magnesium hydroxide microsphere in functional thermosensitive hydrogel for treating neuropathic pain by So-Yeon Park, Joon Hyuk Jung, Da-Seul Kim, Jun-Kyu Lee, Byeong Gwan Song, Hae Eun Shin, Ji-Won Jung, Seung-Woon Baek, Seungkwon You, Inbo Han and Dong Keun Han in Journal of Tissue Engineering</p

sj-docx-1-tej-10.1177_20417314231226105 – Supplemental material for Therapeutic potential of luteolin-loaded poly(lactic-co-glycolic acid)/modified magnesium hydroxide microsphere in functional thermosensitive hydrogel for treating neuropathic pain

Supplemental material, sj-docx-1-tej-10.1177_20417314231226105 for Therapeutic potential of luteolin-loaded poly(lactic-co-glycolic acid)/modified magnesium hydroxide microsphere in functional thermosensitive hydrogel for treating neuropathic pain by So-Yeon Park, Joon Hyuk Jung, Da-Seul Kim, Jun-Kyu Lee, Byeong Gwan Song, Hae Eun Shin, Ji-Won Jung, Seung-Woon Baek, Seungkwon You, Inbo Han and Dong Keun Han in Journal of Tissue Engineering</p