A gram-scale, low-cost and sustainable synthesis of single-crystalline graphene quantum dots derived from biomass waste.

Acquired heterotopic ossification (HO) is a painful and debilitating disease characterized by extraskeletal bone formation after injury. The exact pathogenesis of HO remains unknown. Here we show that TGF-β initiates and promotes HO in mice. We find that calcified cartilage and newly formed bone resorb osteoclasts after onset of HO, which leads to high levels of active TGF-β that recruit mesenchymal stromal/progenitor cells (MSPCs) in the HO microenvironment. Transgenic expression of active TGF-β in tendon induces spontaneous HO, whereas systemic injection of a TGF-β neutralizing antibody attenuates ectopic bone formation in traumatic and BMP-induced mouse HO models, and in a fibrodysplasia ossificans progressive mouse model. Moreover, inducible knockout of the TGF-β type II receptor in MSPCs inhibits HO progression in HO mouse models. Our study points toward elevated levels of active TGF-β as inducers and promoters of ectopic bone formation, and suggest that TGF-β might be a therapeutic target in HO.

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Physical barriers are commonly used to reduce peritendinous adhesion after injury. However, the inflammatory response to surgery cannot be prevented. This study was designed to evaluate the ability of ibuprofen-loaded poly(l-lactic acid)-polyethylene glycol (PELA) diblock copolymer fibrous membranes in preventing adhesion formation and reduce inflammation. Electrospun PELA fibrous membranes underwent mechanical testing and were characterized by morphology, surface wettability, drug release, and degradation. Results of an in vitro drug release study showed that a burst release was followed by sustained release from fibrous membranes with high initial ibuprofen content. Fewer L929 mouse fibroblasts adhered to and proliferated on the ibuprofen-loaded PELA fibrous membrane compared with tissue culture plates or PELA fibrous membrane without ibuprofen. In a chicken model of flexor digitorum profundus tendon surgery, the ibuprofen-loaded PELA fibrous membranes prevented tissue adhesion and significantly reduced inflammation. Taken together, these results demonstrate that ibuprofen-loaded PELA fibrous membranes prevent peritendinous adhesion formation better than membranes that do not contain ibuprofen, through anti-adhesion and anti-inflammatory actions.

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