| Background Abdominal hernia is a common disease in surgical clinic.It refers to permanent or recurrent protrusion of abdominal contents through abdominal wall defect.Patch repair is a common method in clinical treatment of this disease.Current clinical commonly used patch has good mechanical strength,but because of its not absorb,retained for a long time in local,bring to patients with a series of side effects,including pain,infection,relapse and so on,even on clinical abdominal wall hernia operation method is varied,but all need traditional suture or nail fixed patch,This not only is not conducive to postoperative recovery and prolong the operation time,but also has high requirements for the operation of the operator.Objective To design a kind of hydrogel patch with high adhesion and strong mechanical strength in wet state.Method Dopamine(DA)was grafted to Carboxymethyl cellulose(CMC),Poly(Vinyl alcohol)(PVA)was added to Carboxymethyl cellulose(CMC)and dopaminide(DA)was grafted to Carboxymethyl cellulose(CMC).Then,CMC-DA/PVA hydrogel and3D-printed Thermoplastic Urethane(TPU)mesh were poured into Microneedles(MNs)mold.Thus,CMC-DA/PVA hydrogel MNs mesh was obtained.The structure of hydrogel MNs was detected by ~1H NMR,UV spectrophotometer and scanning electron microscope,and the mechanical strength,mechanical properties,adhesion and cytocompatibility of hydrogel MNs were measured.Thirty SD rats were divided into control group(Polypropylene mesh group),MNs surface group and Smooth surface group according to random number table method,with 10 rats in each group,to establish abdominal wall defect rat model.The polypropylene mesh group was sutured on the defect edge with silk thread.The rats were sacrificed on 14 days and 28 days,and the granulation tissue above the defect was cut.The pathological changes of the new granulation tissue were observed under light microscope,and the expressions of CD31 andα-SMA were detected.Measurement data were expressed by means of Mean±standard deviation(Mean±SD).Two independent sample t test was used for comparison between groups with homogeneity of variance,and rank sum test was used for comparison with non-homogeneity of variance,using P<0.05 was considered statistically significant.Results The characteristic absorption peak of the prepared CMC-DA/PVA hydrogel MNs mesh was observed at 280nm,which proved that CMC was successfully grafted onto DA,and the microne structure was observed under scanning electron microscope.The mechanical properties of the hydrogel MNs mesh were measured by universal mechanics machine,which proved that the mechanical strength of the whole hydrogel MNs was improved due to the addition of TPU mesh.The hydrogel MNs mesh can be used as a short plate for the repair of abdominal wall defect,and it is proved to have high adhesion under wet condition by lap shear test.In vitro cell experiments showed that CMC-DA/PVA hydrogel MNs mesh could significantly promote the repair of full-thickness abdominal wall defect in rats.Histomatological evaluation showed that the designed hydrogel mesh promoted collagen formation,induced neovascularization,increased abdominal wall tissue thickness and reconstruction of abdominal wall integrity,and inhibited inflammatory response by decreasing the expression of IL-6,TNF-αand IL-1βcompared with the commercially used polypropylene mesh.At the same time,3D printed stents exist,which can be customized according to the abdominal wall defect.Conclusion CMC-DA/PVA hydrogel MNs patch has good mechanical strength and high adhesion under wet conditions,and can promote the growth of new granulation tissue and inhibit the expression of inflammatory factors.This new hydrogel patch has great potential in the treatment of full-thickness abdominal wall defect. |
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