Addition of heparin binding sites strongly increases the bone forming capabilities of BMP9 in vivo

Bone Morphogenetic proteins(BMPs)like BMP2 and BMP7 have shown great potential in the treatment of severe bone defects.In recent in vitro studies,BMP9 revealed the highest osteogenic potential compared to other BMPs,possibly due to its unique signaling pathways that differs from other osteogenic BMPs.However,in vivo the bone forming capacity of BMP9-adsorbed scaffolds is not superior to BMP2 or BMP7.In silico analysis of the BMP9 protein sequence revealed that BMP9,in contrast to other osteogenic BMPs such as BMP2,completely lacks so-called heparin binding motifs that enable extracellular matrix(ECM)interactions which in general might be essential for the BMPs’osteogenic function.Therefore,we genetically engineered a new BMP9 variant by adding BMP2-derived heparin binding motifs to the N-terminal segment of BMP9′s mature part.The resulting protein(BMP9 HB)showed higher heparin binding affinity than BMP2,similar osteogenic activity in vitro and comparable binding affinities to BMPR-II and ALK1 compared to BMP9.However,remarkable differences were observed when BMP9 HB was adsorbed to collagen scaffolds and implanted subcutaneously in the dorsum of rats,showing a consistent and significant increase in bone volume and density compared to BMP2 and BMP9.Even at 10-fold lower BMP9 HB doses bone tissue formation was observed.This innovative approach of significantly enhancing the osteogenic properties of BMP9 simply by addition of ECM binding motifs,could constitute a valuable replacement to the commonly used BMPs.The possibility to use lower protein doses demonstrates BMP9 HB’s high translational potential.

Microorganism-derived biological macromolecules for tissue engineering

According to literature,certain microorganism productions mediate biological effects.However,their beneficial characteristics remain unclear.Nowadays,scientists concentrate on obtaining natural materials from live creatures as new sources to produce innovative smart biomaterials for increasing tissue reconstruction in tissue engineering and regenerative medicine.The present review aims to introduce microorganism-derived biological macromolecules,such as pullulan,alginate,dextran,curdlan,and hyaluronic acid,and their available sources for tissue engineering.Growing evidence indicates that these materials can be used as biological material in scaffolds to enhance regeneration in damaged tissues and contribute to cosmetic and dermatological applications.These natural-based materials are attractive in pharmaceutical,regenerative medicine,and biomedical applications.This study provides a detailed overview of natural-based biomaterials,their chemical and physical properties,and new directions for future research and therapeutic applications.