Engineering the next generation of theranostic biomaterials with synthetic biology

Biomaterials have evolved from inert materials to responsive entities,playing a crucial role in disease diagnosis,treatment,and modeling.However,their advancement is hindered by limitations in chemical and mechanical approaches.Synthetic biology enabling the genetically reprograming of biological systems offers a new paradigm.It has achieved remarkable progresses in cell reprogramming,engineering designer cells for diverse applications.Synthetic biology also encompasses cell-free systems and rational design of biological molecules.This review focuses on the application of synthetic biology in theranostics,which boost rapid development of advanced biomaterials.We introduce key fundamental concepts of synthetic biology and highlight frontier applications thereof,aiming to explore the intersection of synthetic biology and biomaterials.This integration holds tremendous promise for advancing biomaterial engineering with programable complex functions.

Injectable ECM hydrogel for delivery of BMSCs enabled full-thickness meniscus repair in an orthotopic rat model

Meniscal injuries have poor intrinsic healing capability and are associated with the development of osteoarthritis.Decellularized meniscus extracellular matrix(mECM)has been suggested to be efficacious for the repair of meniscus defect.However,main efforts to date have been focused on the concentration,crosslinking density and anatomical region dependence of the mECM hydrogels on regulation of proliferation and differentiation of adult mesenchymal stem cells(MSCs)in vitro 2D or 3D culture.A systematic investigation and understanding of the effect of mECM on encapsulated MSCs response and integrative meniscus repair by in vivo rat subcutaneous implantation and orthotopic meniscus injury model will be highly valuable to explore its potential for clinical translation.In this study,we investigated the in situ delivery of rat BMSCs in an injectable mECM hydrogel to a meniscal defect in a SD rat model.Decellularized mECM retained essential proteoglycans and collagens,and significantly upregulated expression of fibrochondrogenic markers by BMSCs versus collagen hydrogel alone in vitro 3D cell culture.When applied to an orthotopic model of meniscal injury in SD rat,mECM is superior than collagen I scaffold in reduction of osteophyte formation and prevention of joint space narrowing and osteoarthritis development as evidenced by histology and micro-CT analysis.Taken together,these results indicate mECM hydrogel is a highly promising carrier to deliver MSCs for long-term repair of meniscus tissue,while preventing the development of osteoarthritis.