Preparation, properties, and cell attachment/growth behavior of chitosan/acellular derm matrix composite materials

Composite membranes and sponge scaffolds consisting chitosan (CS) and acellular derm matrix (ADM) in six ratios were prepared by solvent evaporation technique and freeze-drying method, respectively. The composite materials were characterized by water contact angle measurement, scanning electron microscopy (SEM), water absorption and HaCat cells compatibility. The SEM result showed that CS/ADM three-dimensional (3D) micro-porous structures were successfully produced. The water absorption value of all scaffolds was over 18 times of its initial weight, which is high enough for skin regeneration scaffold, but there were no significant differences of water absorption ratio between deionized water and PBS solution for same scaffold (P > 0.05). HaCat cells were distributed uniformly on the surfaces of membrane 4-6, and an almost confluent monolayer was formed on membrane 6 on the fifth day, whereas cells maintained round and spherical in shape on the surface of membrane 1. The results showed that the cell compatibility of pure CS membrane needed to be improved, and addition of ADM realized this purpose. The results of compatibility of HaCat cells on scaffolds showed that the cell proliferated well on the scaffolds 3 and 4. In our study, the cell’s attachment and growth on the composite membranes was mainly determined by the content of the membrane, whereas the cell’s attachment and growth in the scaffolds was determined by both the content and structure of the scaffolds.

Macrophage phenotypes correspond with remodeling outcomes of various acellular dermal matrices

Macrophages have recently been characterized as having an M1 or M2 phenotype based on receptor expression, mechanism of activation and function. The effects of macrophage phenotype upon tissue remodeling following implantation of an acellular dermal matrix (ADM) is largely unknown. The purpose of this study was to compare the macrophage phenotype and tissue remodeling elicited by four different ADMs (DermaMatrix, AlloDerm, Integra and Der mACELL). ADM samples were wrapped around the inferior epigastric vessels of a rat and were harvested on 7, 14, 21 and 42 days post implantation. Immunohistologic methods were used to identify macrophage surface markers CD68 (pan macrophage), CCR7 (M1 profile), and CD206 (M2 profile). All human derived ADMs showed a bell shaped curve for distribution of CD68+ macrophages with peaks for DermaMatrix occurring at day 14 and peak influx for AlloDerm occurring on day 21. In contrast, bovine derived Integra showed an increasing trend of macrophages with time. DermACELL had the highest influx of macro- phages while Integra had the lowest. A quantitative analysis of phenotype of macrophages in AlloDerm showed that the cells were predominantly M1 at 7, 14, 21 and 42 days post implantation. In contrast, Integra showed a mixed M1/M2 population of macrophages at all time points. The histopathologic evaluation showed that a predominantly M1 macrophage response was associated with a more inflamematory type tissue remodeling outcome in AlloDerm while a mixed M1/M2 macrophage response was associated with a more constructive tissue remodeling response seen in the other substrates.

脱细胞基质补片填充鼻唇沟

目的探索脱细胞真皮基质医用组织补片在鼻唇沟填充术中的应用方法自2021年9月~2022年4月,经鼻翼内侧切口,松解并剥离鼻唇沟皮下黏膜组织,应用脱细胞真皮基质医用组织补片填充于双侧鼻唇沟软组织凹陷区,依据患者双侧鼻唇沟软组织凹陷不同程度适用相应材料量。所有病例随访3~6个月。结果本组28例病患除1例单侧因组织补片放置不平整导致口腔黏膜穿出而取出重放,另1例术后2天病患自觉填充区皮肤及皮下肿胀、疼痛取出,其余的26例都取得了满意效果。结论脱细胞真皮基质医用组织补片填充双侧鼻翼基底凹陷矫正手术效果明显,在临床应用中,具有良好的组织相容性及支撑作用,且鼻翼内侧切口有着手术操作简单、损伤微小、不易感染、易成活等特点。明确的优点在于避免了固定形态的假体类材料压迫神经造成口周麻木问题,降低了在鼻唇沟参与的动态表情随面部肌肉皮肤的活动的僵硬感、体表轮廓感以及包膜形成前移位的风险,是一种相对理想的鼻唇沟填充生物材料。