Plant-inspired adhesive and injectable natural hydrogels: in vitro and in vivo studies.

The development of alternative therapeutic treatments based on the use of medicinal and aromatic plants, such as Juniper communis L., has aroused interest in the medical field to find new alternatives to conventional therapeutic treatments, which have shown problems related to bacterial resistance, high costs, or sustainability in their production. The present work describes the use of hydrogels based on sodium alginate and carboxymethyl cellulose, with combinations of juniperus leaves and berry extracts, in order to characterize their chemical characteristics, antibacterial activity, tissue adhesion test, cytotoxicity in the L929 cell line, and their effects on an in vivo model in mice to maximize the use of these materials in the healthcare field. Overall, an adequate antibacterial potential against S. aureus, E. coli and P. vulgaris was obtained with doses above 100 mg.mL-1 of hydrogels. Likewise, low cytotoxicity in hydrogels combined with extracts has been identified according to the IC50 value at 17.32 µg.mL-1, compared to the higher cytotoxic activity expressed by the use of control hydrogels with a value at 11.05 µg.mL-1. Moreover, in general, the observed adhesion was high to different tissues, showing its adequate capacity to be used in different tissue typologies. Furthermore, the invivo results have not shown erythema, edema, or other complications related to the use of the proposed hydrogels. These results suggest the feasibility of using these hydrogels in biomedical applications given the observed safety.

Novel Bioactive Glass/Graphene Oxide-Coated Surgical Sutures for Soft Tissue Regeneration.

The combination of a commercially available PGLA (poly[glycolide-co-l-lactide]), 90:10% suture material with bioactive bioglass nanopowders (BGNs) and graphene oxide (GO)-doped BGNs offers new opportunities for the clinical application of biomaterials in soft tissue engineering. In the present experimental work, we demonstrate that GO-doped melt-derived BGNs were synthesized via the sol-gel process. After that, novel GO-doped and undoped BGNs were used to coat resorbable PGLA surgical sutures, thereby imparting bioactivity, biocompatibility, and accelerated wound healing properties to the sutures. Stable and homogeneous coatings on the surface of the sutures were achieved using an optimized vacuum sol deposition method. The phase composition, morphology, elemental characteristics, and chemical structure of uncoated and BGNs- and BGNs/GO-coated suture samples were characterized using Fourier transform infrared spectroscopy, field emission scanning electron microscopy, associated with elemental analysis, and knot performance test. In addition, in vitro bioactivity tests, biochemical tests, and in vivo tests were performed to examine the role of BGNs and GO on the biological and histopathological properties of the coated suture samples. The results indicated that the formation of BGNs and GO was enhanced significantly on the suture surface, which allowed for enhanced fibroblast attachment, migration, and proliferation and promoted the secretion of the angiogenic growth factor to speed up wound healing. These results confirmed the biocompatibility of BGNs- and BGNs/GO-coated suture samples and the positive effect of BGNs on the behavior of L929 fibroblast cells and also showed for the first time the possibility that cells can adhere and proliferate on the BGNs/GO-coated suture samples, especially in an in vivo environment. Resorbable surgical sutures with bioactive coatings, such as those prepared herein, can be an attractive biomaterial not only for hard tissue engineering but also for clinical applications in soft tissue engineering.