Chen Yuan,Shue Jin,Jiawei Wei,Jinhui Huang,Chang Liu,Xiaoyu Lei,Yi Zuo,Jidong Li,Yubao Li
The deformation shrinkage of a poly(lactide-co-glycolide) (PLGA) fibrous material seriously affects its biomedical application. To demonstrate the underlying shrinking mechanism and to find a method to prevent the shrinkage of an electrospun PLGA membrane, we investigated the shrinking behavior of PLGA electrospun membranes under various test conditions and discussed the underlying shrinking mechanism. The results indicated that the shrinkage of the electrospun PLGA membrane was mainly regulated by the glass transition of its polymer fiber; the temperature and liquid environment were found to be the two main factors leading to the shrinkage of the electrospun PLGA membrane through affecting its glass transition. Then a heat stretching (HS) technique was proposed by us to stabilize the electrospun PLGA membrane. After HS treatment, the glass transition temperature (Tg) of the electrospun PLGA membrane could increase from 48.38 °C to 54.55 °C. Our results indicated that the HS-treated membranes could maintain a high area percentage of 90.89 ± 2.27% and 84.78 ± 3.36% after immersion respectively in PBS and blood at 37 °C for 2 hours. Further experiments confirmed that the HS technique could also stabilize the dimensional structure of the electrospun PDLLA membrane in PBS and blood at 37 °C. This study provides an effective strategy for preventing the shrinkage of electrospun polyester biomaterials in a physiological environment that may benefit both the material structural stability and the in vivo biological performance.
The treatment of infected irregular wounds remains one of the most significant challenges in clinical practice. Sprayable hydrogels have attracted considerable attention due to their favorable fitting with irregular wounds. However, the development of hydrogels with programmable anti-bacterial, anti-inflammatory, and regenerative properties to match the healing process still faces severe challenges. Herein, a versatile strategy is demonstrated to develop sprayable and photothermal fiber-embedded hydrogel dressings by incorporating the gold nanorods (AuNRs) and anti-inflammatory drug diclofenac sodium (DS)-loaded poly(lactic- co -glycolic acid) (PLGA) electrospun fibers into the stromal-cell-derived factor 1α (SDF-1α)-immobilized gelatin methacrylate hydrogel. Benefiting from the photothermal conversion property of AuNRs and the suitable glass transition temperature of PLGA short fibers, the hydrogels can not only realize a photothermal anti-bacterial effect, but also photo-triggered on-demand release of DS for anti-inflammatory activity. Furthermore, the sustained release of SDF-1α facilitates endogenous stem cell recruitment. The in vivo experiments demonstrate accelerated healing of infected wounds. The RNA-sequencing analysis reveals that the hydrogel is capable of suppressing the inflammatory response-related pathway. The photo-responsive fiber-embedded hydrogels offer a promising strategy for constructing a photo-triggered programmable therapeutic platform for regenerative medicine.
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