Extracellular matrix hydrogel has been widely used in three-dimensional cell culture, organoid construction, tissue defect repair, biological three-dimensional printing and tissue engineering due to its excellent bioactivity, biocompatibility, bioinducibility, biodegradability and minimally invasive injection. Adipose tissue has the advantages of sufficient sources, easy access, and rich content of extracellular matrix components. It has become a research hotspot in the field of tissue repair and regenerative medicine in recent years. This article reviews its preparation, detection and application, in order to provide a reference for relevant researchers.

Extracellular matrix hydrogel has been widely used in three-dimensional cell culture, organoid construction, tissue defect repair, biological three-dimensional printing and tissue engineering due to its excellent bioactivity, biocompatibility, bioinducibility, biodegradability and minimally invasive injection. Adipose tissue has the advantages of sufficient sources, easy access, and rich content of extracellular matrix components. It has become a research hotspot in the field of tissue repair and regenerative medicine in recent years. This article reviews its preparation, detection and application, in order to provide a reference for relevant researchers.

The clinical demands for tissue and organ regeneration ars increasing. three-dimensional bioprinting can not only solve the problem of tissue replacement and regeneration, but also meet the personalized needs of patients by constructing highly bionic tissues and functional substitutes of active tissues and organs. So, it has broad application potential in orthopedics. The authors mainly introduce the main progress of 3D bioprinting in basic research of orthopedics such as bone tissue printing, cartilage tissue printing, biphasic printing of bone and cartilage as well as in clinical application of traumatic orthopedics, which may provide reference for clinical application of 3D bioprinting.

Objective:To explore the establishment and assessment of the depression model of adult SD rats induced by early maternal infant separation stress combined with adult chronic unpredictable mild stress(CUMS), and to observe the behavior and synaptic protein expression of SD rats.Methods:Twenty-four male rats were randomly divided into three groups: control group (CON group), chronic unpredictable stress group (CUMS group), maternal infant separation combined with chronic unpredictable stress group (MS + CUMS group). The depression model of rats in cums group was established by CUMS, and the depression model of rats in MS + CUMS group was established by maternal infant separation + CUMS. The depression model was evaluated by body mass and appearance observation, sugar water preference experiment, open field test and forced swimming test.Synapse-associated proteins (PSD-95 and synaptophysin (Syn)) of the hippocampus were assayed using Western blot. Syn protein expression was measured by immunohistochemistry.Results:After modeling, compared with CON group, the rats in CUMS group and MS + CUMS group had significantly lower body mass((126.43±3.88) g, (91.04±3.85) g, (69.89±6.67) g; t=5.03, 8.03, both P<0.01), significantly lower sugar water preference((94.21±0.56)%, (79.30±1.13)%, (72.73±1.82)%; t=8.24, 11.87, both P<0.01) and significantly increased immobility time((3.50±0.84)s, (13.59±2.40)s, (15.70±2.97)s; t=3.16, 3.82, both P<0.01). Among them, the body mass and sugar water preference of MS + CUMS group were lower than those of CUMS group ( t=3.00, 3.63; both P<0.01). (2)The center time of the rats in MS+ CUMS group markedly reduced compared with that of CON group((21.41±4.65) s, (8.96±2.37) s; t=2.66, P<0.05). (3)In the immunohistochemistry experiment, compared with the CON group, the percentage of Syn positive area in hippocampus of rats in CUMS group and MS+ CUMS group decreased significantly ((24.42±0.76)%, (14.00±0.95)%, (10.38±1.38)%; t=6.93, 9.33, P<0.01). (4)The results of Western blot showed that compared with CON group, both the expression of PSD-95 ((1.18±0.02), (0.74±0.06), (0.52±0.05), t=6.29, 9.31; both P<0.05) and Syn ((1.12±0.08), (0.95±0.06), (0.90±0.07); t=3.10, 4.04; both P<0.05) in hippocampus of rats in CUMS group and MS+ CUMS group were significantly decreased.And compared with the CUMS group, the expression of PSD-95 in MS+ CUMS group was lower( t=0.93, P<0.05). Conclusion:The method of MS combined with CUMS can effectively induce depression like behavior and decrease the expression of synaptic plasticity related protein of hippocampus in rats.

Objective To explore variety of suture methods in the prevention or reduction of calcaneal fracture incision complications.Methods The data on 120 patients receiving open reduction and internal fixation of the calcaneus fractures in our hospital from January 2014 to December 2015 were collected.A lateral L-like incisionwas used.Allgower-Donati suture,interrupted vertical mattress suture,intradermal suture,and interrupted suture were applied to manage the incision.The incidence of tension blisters in the incision and its surrounding areas,skin flap necrosis,stitch-cutting edge in the skin,and plate exposure was statistically analyzed.The SPSS 18.0 was used for statistical analysis,and P ＜ 0.05 was statistically significant.Results Postoperative complication rate was 6.7％ for Allgower-Donati suture,13.3％ for interrupted vertical mattress suture,26.7％ for intradermal suture and 33.3％ for interrupted suture (P ＜ 0.05).Conclusions Allgower-Donati suture can prevent or reduce wound complications of calcaneal fractures effectively,and it is worthy of extensive clinical use.