Department of Hematology and Research Laboratory of Hematology, State Key Laboratory of Biotherapy, West China Hospital, Sichuan University and Collaborative Innovation Center , Sichuan, China.
ACS Appl Mater Interfaces. 2018 Feb 7;10(5):4462-4470. doi: 10.1021/acsami.7b17020. Epub 2018 Jan 26.
Spinal fusion is the classic treatment to achieve spinal stability for the treatment of the spinal disease. Generally, spinal fusion still has to combine a certain of bone matrix for promoting bone formation to achieve the desired fusion effect based on the surgery, including the traditional bone matrix, such as the autologous bone, allografts and xenografts. Nevertheless, some problems still existed such as the immunogenic problems, the secondary wound, and pathogenic transfer and so on. Here the injectable thermosensitive hydrogel could substitute to avoid the problems as a potential biological scaffold for tissue engineering. Once injected, they could fill in the irregular-shaped cavity and change to a gel state at physiological temperature. We wanted to design the collagen/n-HA/BMP-2@PCEC/PECE hydrogel composites based on previous work about collagen/n-HA/PECE hydrogel to exhibit better performance in guiding spinal fusion because of the addition of BMP-2@PCEC nanoparticles (PCEC, PCL-PEG-PCL). However, when the hydrogels were injected, one of the surfaces was in contact with the spine, but others were in contact with soft tissue like muscles and fascia. The release behavior was the same at the different surfaces, so the factors could be released into the soft tissue, and it may then be consumed or lead to ectopic bone formation. The hydrogel composites should be improved to adjust the direction of the releaser behavior. In consequence, we wrapped an electrostatic spinning nanofiber membrane possessing hydrophobicity around the hydrogels. In this study, we developed a system that the collagen/n-HA/BMP-2@PCEC/PECE hydrogels were wrapped with the hydrophobicity PDLLA electrospun nanofiber membrane, setting up a barrier between the hydrogels and the soft tissue. The system could exhibit biocompatibility, preventing the factors from escaping to keep their retention in the needed places of osteogenesis; the results demonstrated that it showed an excellent effect on spinal fusion.
脊柱融合是实现脊柱稳定性以治疗脊柱疾病的经典治疗方法。通常，脊柱融合仍然需要结合一定的骨基质来促进骨形成，以达到手术所需的融合效果，包括传统的骨基质，如自体骨、同种异体骨和异种骨。然而，仍然存在一些问题，如免疫问题、二次创伤和病原体转移等。在这里，可注射温敏水凝胶可以替代传统骨基质，作为组织工程的潜在生物支架来避免这些问题。一旦注入，它们可以填充不规则形状的腔，并在生理温度下转变为凝胶状态。我们希望在以前关于胶原/n-HA/PECE 水凝胶的工作基础上，设计胶原/n-HA/BMP-2@PCEC/PECE 水凝胶复合材料，以在引导脊柱融合方面表现出更好的性能，因为添加了 BMP-2@PCEC 纳米粒子（PCEC，PCL-PEG-PCL）。然而，当水凝胶被注入时，一个表面与脊柱接触，但其他表面与肌肉和筋膜等软组织接触。在不同的表面，释放行为是相同的，因此，这些因素可能会释放到软组织中，并且可能被消耗或导致异位骨形成。水凝胶复合材料应进行改进，以调整释放剂行为的方向。因此，我们在水凝胶周围包裹了一层具有疏水性的静电纺纳米纤维膜。在这项研究中，我们开发了一种系统，即胶原/n-HA/BMP-2@PCEC/PECE 水凝胶被具有疏水性的 PDLLA 静电纺纳米纤维膜包裹，在水凝胶和软组织之间形成一道屏障。该系统具有良好的生物相容性，可以防止因子逸出，保持它们在成骨所需的位置保留；结果表明，它在脊柱融合方面表现出了极好的效果。
