Binding efficiency of recombinant collagen-binding basic fibroblast growth factors (CBD-bFGFs) and their promotion for NIH-3T3 cell proliferation

The extracellular matrix with a continuous gradient of SDF1αguides the oriented migration of human umbilical cord mesenchymal stem cells

The extracellular matrix (ECM) plays a crucial role in maintaining cell morphology and facilitating intercellular signal transmission within the human body. ECM has been extensively utilized for tissue injury repair. However, the consideration of factor gradients during ECM preparation has been limited. In this study, we developed a novel approach to generate sheet-like ECM with a continuous gradient of stromal cell-derived factor-1 (SDF1α). Briefly, we constructed fibroblasts to overexpress SDF1αfused with the collagen-binding domain (CBD-SDF1α), and cultured these cells on a slanted plate to establish a gradual density cell layer at the bottom surface. Subsequently, excess parental fibroblasts were evenly distributed on the plate laid flat to fill the room between cells. Following two weeks of culture, the monolayer cells were lyophilized to form a uniform ECM sheet possessing a continuous gradient of SDF1α. This engineered ECM material demonstrated its ability to guide oriented migration of human umbilical cord mesenchymal stem cells on the ECM sheet. Our simple yet effective method holds great potential for advancing research in regenerative medicine.

Research progress of biomaterials and innovative technologies in urinary tissue engineering

Substantial interests have been attracted to multiple bioactive and biomimetic biomaterials in recent decades because of their ability in presenting a structural and functional reconstruction of urinary tissues. Some innovative technologies have also been surging in urinary tissue engineering and urological regeneration by providing insights into the physiological behavior of the urinary system. As such, the hierarchical structure and tissue function of the bladder, urethra, and ureter can be reproduced similarly to the native urinary tissues. This review aims to summarize recent advances in functional biomaterials and biomimetic technologies toward urological reconstruction. Various nanofirous biomaterials derived from decellularized natural tissues, synthetic biopolymers, and hybrid scaffolds were developed with desired microstructure, surface chemistry, and mechanical properties. Some growth factors, drugs, as well as inorganic nanomaterials were also utilized to enhance the biological activity and functionality of scaffolds. Notably, it is emphasized that advanced approaches, such as 3D (bio) printing and organoids, have also been developed to facilitate structural and functional regeneration of the urological system. So in this review, we discussed the fabrication strategies, physiochemical properties, and biofunctional modification of regenerative biomaterials and their potential clinical application of fast-evolving technologies. In addition, future prospective and commercial products are further proposed and discussed.

Acceleration of Healing in Full-Thickness Wound by Chitosan-Binding bFGF and Antimicrobial Peptide Modification Chitosan Membrane

Skin wound healing is an important clinical challenge, and the main treatment points are accelerating epidermal regeneration and preventing infection. Therefore, it is necessary to develop a wound dressing that can simultaneously cure bacterial infections and accelerate wound healing. Here, we report a multifunctional composite wound dressing loaded with chitosan (CS)-binding bFGF (CSBD-bFGF) and antimicrobial peptides (P5S9K). First, CS was used as the dressing matrix material, and P5S9K was encapsulated in CS. Then, CSBD-bFGF was designed by combining recombinant DNA technology and tyrosinase treatment and modified on the dressing material surface. The results show that the binding ability of CSBD-bFGF and CS was significantly improved compared with that of commercial bFGF, and CSBD-bFGF could be controllably released from the CS dressing. More importantly, the prepared dressing material showed excellent antibacterial activity in vivo and in vitro and could effectively inhibit the growth of E. coli and S. aureus. Using NIH3T3 cells as cellular models, the results showed that the CSBD-bFGF@CS/P5S9K composite dressing was a friendly material for cell growth. After cells were seeded on the composite dressing surface, collagen-1 (COL-1) and vascular endothelial growth factor (VEGF) genes expression in cells were significantly upregulated. Finally, the full-thickness wound of the rat dorsal model was applied to analyse the tissue repair ability of the composite dressing. The results showed that the composite dressing containing CSBD-bFGF and P5S9K had the strongest ability to repair skin wounds. Therefore, the CSBD-bFGF@CS/P5S9K composite dressing has good antibacterial and accelerated wound healing abilities and has good application prospects in the treatment of skin wounds.

A functional extracellular matrix biomaterial enriched with VEGFA and bFGF as vehicle of human umbilical cord mesenchymal stem cells in skin wound healing

The construction of microvascular network is one of the greatest challenges for tissue engineering and cell therapy. Endothelial cells are essential for the construction of network of blood vessels. However, their application meets challenges in clinic due to the limited resource of autologous endothelium. Mesenchymal stem cells can effectively promote the angiogenesis in ischemic tissues for their abilities of endothelial differentiation and paracrine, and abundant sources. Extracellular matrix (ECM) has been widely used as an ideal biomaterial to mimic cellular microenvironment for tissue engineering due to its merits of neutrality, good biocompatibility, degradability, and controllability. In this study, a functional cell derived ECM biomaterial enriched with VEGFA and bFGF by expressing the collagen-binding domain fused factor genes in host cells was prepared. This material could induce endothelial differentiation of human umbilical cord mesenchymal stem cells (hUCMSCs) and promote angiogenesis, which may improve the healing effect of skin injury. Our research not only provides a functional ECM material to inducing angiogenesis by inducing endothelial differentiation of hUCMSCs, but also shed light on the ubiquitous approaches to endow ECM materials different functions by enriching different factors. This study will benefit tissue engineering and regenerative medicine researches.