The differentiation of stem cells into target cells in a particular region is an important prerequisite for the organ construction and tissue engineering. The processes are multi-directionally regulated by the surface properties of biomaterials, and among them the influences of mechanical rigidity and surface morphology of biomaterials on morphological characteristics, focal adhesion assemblies, and cytoskeletal structure of cells are considered to be the most important factors in regulating the differentiation of stem cells into specific cell lineages. This review summarizes the progresses on this topic in the past few years, which may provide a reference to the design of the biomaterials in regenerative medicine and tissue engineering.
Biocompatible Materials ; metabolism ; Cell Differentiation ; Cell Lineage ; Humans ; Musculoskeletal System ; cytology ; metabolism ; Regenerative Medicine ; Stem Cells ; cytology ; Surface Properties ; Tissue Engineering

Objective To discuss the therapeutic effects and safety of external ultrasound liposuction to adipose tissue of lower extremities and to summarize the operative techniques. Methods According to the requests of 81 patients, external ultrasound liposuction were performed for them on thighs (n=60), and legs (n=21). It was that the volumes of anesthetic drugs and pure fat as well as the variations of body contour between preoperation and one to three months after operation in every area were recorded. Results Fat aspiration volume in thighs was 3673ml per person with the highest 6100ml. The scale of the circumference of thighs decrease (4.65?1.10)cm with the highest 12.5 cm. In legs, fat volume was 650ml per person with the highest 1200ml, scale decrease (3?1.02) cm with the highest 9cm. Patients had less blood loss, less pain and discomfort with even skin appearance and without severe complications. In the course of operation, knowing well the anatomical character of lower extremities, injecting the anesthetic drugs completely, using appropriate ultrasound time, and sucking in uniform layer were all crucial factors to guarantee the success of the operation. Conclusion External ultrasound liposuction is a safe, effective body contour remodeling operation in lower extremities. Skillful operator is a very important element to successful operation.

Objective To evaluate the long term effect of acellular allogeneic nerve grafting combined with exogenous basic fibroblast growth factor (bFGF) in peripheral nerve repair. Methods Sixteen big-ear Japanese rabbits were divided into experimental and control groups randomly. In the experimental group, 3 cm-long acellular allogeneic nerves from New Zealand rabbit were used to bridge the rabbit tibial nerve defects; and 1 ml bFGF solution was given from the second day once daily for 2 weeks and twice a week for another 6 weeks after surgery. In the control group, normal saline solution was given. Morphological and functional results were evaluated 20 weeks after the nerve repair. Results The recovery rates of the evoked potential and the nerve conduction velocity in the experimental group were 67.59%?29.63% and 59.79%?21.11%, respectively, significantly higher than that (49.07%? 15.74% and 36.85%?18.69% respectively) in the control group (P

Objective To investigate the efficacy of one-stage posterior procedure including reduction, segmental instrumentation, foraminal enlargement and interbody compressive fusion in treating traumatic thoracolumbar fracture and dislocation. Methods 17 patients, which were 11 males and 6 females with a mean age of 37.1 years (range, 23-56 years) were recruited. The injury mechanism consisted of motor vehicle accident, falling from the height and horizontal compression crash. The preoperation neurological function were complete paraplegia in 4 cases, and incomplete paraplegia in 13 cases. Laminectomy and bilateral partial facetectomies were performed in injuried levels to free the nerve roots, followed by intervertebral foraminal enlargement and distraction through inserted pedicle screws. Intervertebral disc including upper and lower endplate were removed with rongeur, and morselized cancellous bone were fulfilled into cavity. Reduction and interbody compressive fusion were achieved through compression on the segmental pedicle screw system to make contact the posterior wall of adjacent vertebrae. Results No intraoperative and postoperative complications were observed. All patients except one underwent successful follow-up for an average of 25.6 months, ranging from 19 to 37 months. The neurological function of the patients were restored partially or complete during follow-up. The thoracolumbar spine were stable during physical examination, and all patients were satisfied with surgery. Radiographic evaluation showed close conjunction of adjacent posterior edges of vertebral body in 12 cases, and all cases demonstrated solid bony fusion without loss of reduction. No implant failure or neurological complication were found during follow-up. Conclusion Interbody compressive fusion by pedicle screws with foraminal enlargement procedure is a reliable and effective method in the management of thoracolumbar fracture and dislocation, which can achieve early stabilization and interbody bony fusion.

Objective To evaluate the promoting effect by bFGF on nerve regeneration following acellular allogeneic nerve grafting,and the effects of various concentration of bFGF on axon growth. Methods The animals were divided into 1 000U/ml, 500U/ml, 250U/ml,100U/ml and normal saline groups. Immunohistochemistry staining of neurofilament-160 and S-100 was used to show the length of axonal growth and Schwann cell infiltration 10 days after the surgery. Results The average distance of regenerated nerve fibers in the high dose groups (1 000U/ml and 500U/ml) was longer than that in the normal saline control group;but there was no difference between the low dose groups (250U/ml and 100U/ml) and the control group. Conclusion Early use of bFGF when acellular allogeneic nerve grafted to bridge peripheral nerve defect may obviously promote axon growth speed.

Objective To observe the granule tissue remodeling under neoepithelium in minitype pigs' full thickness dermal wounds and discuss the relation between the remodeling and possible ulcers or scars. Methods After the establishment of eight full-thickness dermal wound models with the diameter of 4 cm on the back of six minitype pigs, the specimens were collected from wound edge and wound center immediately, 3, 6, 9, 12, 15, 20, 25, 30 and 45 days, respectively after injury for HE staining, immunohistochemical staining and Van Gieson staining and then observed under light microscope to count the cell number, fibroblasts and vascular endothelial cells as well as evaluate the quantity and arrangement of collagens. Results The mean wound healing time was (29.3?1.8) days. After 9-25 days, the granule tissues in the wound center contained more cells, fibroblasts, collagen and vascular endothelial cells than those under neoepithelium of wound edge (P 0.01). Meanwhile, the collagen quantity and arrangement style of granule tissues under neoepithelium during wounds healing (12-30 days) assembled those under neoepithelium 15 days after wound healing. Conclusion Granule tissue remodeling exists during the healing of full thickness dermal wound.

Objective To investigate the serotypes of human enterovirus B ( HEV-B) species cau-sing hand, foot and mouth disease ( HFMD) and to analyze the genetic characteristics of VP1 region in cox-sackievirus B2 ( CVB2 ) and coxsackievirus B5 ( CVB5 ) strains circulating in Anyang area during 2011 to 2015. Methods Real-time RT-PCR and semi-nested RT-PCR were performed to identify coxsackievirus A16 (CVA16), enterovirus 71 (EV71) and other serotypes of enterovirus in order to obtain the complete etiologic composition of HFMD. The numbers of HEV-B serotypes and the percentages of specimens positive for every serotype in all enterovirus-positive specimens were calculated. As CVB2 and CVB5 were the pre-dominant serotypes of HEV-B species, five pairs of primers targeting the VP1 regions of CVB2 and CVB5 were designed to obtain the complete nucleotide sequences of CVB2 and CVB5 VP1 regions. The phylogenet-ic trees were constructed based on the VP1 sequences obtained in this study and those submitted to GenBank by using MEGA7. 0 and BioEdit7. 2. The selection pressures on VP1 regions of CVB2 and CVB5 strains cir-culating in China in recent years were evaluated with the online program of DataMonkey. Results A total of 57 specimens that belonged to 14 serotypes of HEV-B species were detected in Anyang area from 2011 to 2015. The 14 serotypes of HEV-B species accounted for 56% of all serotypes of enterovirus and the speci-mens positive for HEV-B species accounted for 3. 06% of all enterovirus-positive specimens. The HFMD ca-ses caused by most of the HEV-B serotypes were sporadic cases. Small outbreaks of HFMD could also be caused by some serotypes of HEV-B such as CVB2 and CVB5. The complete sequences of VP1 region were obtained from 8 CVB2 strains and 9 CVB5 strains. The phylogenetic trees based on the VP1 sequences dem-onstrated that the CVB2 strains were classified into four genotypes ( A-D) . The mean evolutionary distances between different genotypes ranged from 0. 191 to 0. 208 and the similarities in nucleotide sequences ranged from 79. 7% to 85. 8%. The CVB5 strains were classified into 6 genotypes (A-F). The mean evolutionary distances and the similarities in nucleotide sequences between different genotypes of CVB5 strains ranged from 0. 170 to 0. 285 and 76. 0% to 86. 8%, respectively. Strains of different genotypes varied significantly in the residues on positons 157 and 263 in the VP1 region of CVB2 strains and on positions 75, 90 and 95 in the VP1 region of CVB5 strains. All of the CVB2 strains isolated in Anyang area belonged to D genotype and located intensively in one lineage. The CVB5 strains circulated in Anyang area belonged to F genotype and located in two lineages. The selection pressures on CVB2 strains of D genotype and CVB5 strains of F geno-type circulating in China in recent years were 0. 037 and 0. 036, respectively. Six positively selected amino acid sites were found in the VP1 region of CVB5 strains, but no positively selected amino acid site was found in the VP1 region of CVB2 strains. Conclusion HEV-B species was an essential component of the etiologic spectrum of HFMD in Anyang area during 2011 to 2015, of which CVB5 and CVB2 were the predominant se-rotypes. The VP1 region of CVB5 was more complex and active than that of CVB2 over the course of evolution.

Objective To evaluate the biocompatibility of four kinds of polyurethane sponges made in China. Methods According to ASTM Standards for Medical Devices of America, polyurethane sponges are used to perform such biological tests as cytotoxicity test, acute toxicity test, pyrogenic reactions test, stimulation test of conjunctiva and cornea, sensitization test. The data are analyzed and evaluated according to the criterion. Results Reaction scales of these polyurethane sponges in cytotoxicity are 0 or 1 level. No toxicity effects and pyrogenic reactions are observed in vivo test. No conjunctiva and cornea irritation reactions and no sensitization reactions are found. Conclusions The four kinds of polyurethane sponges have high biocompatibility and can become ideal dressings of Vacuum-Assisted Closure.

Objective To test the effect of negative pressure on the rate of skin donor site re-epithelialization in pig model.Methods Five pigs were selected for this study,and two split-thickness skin graft defects were harvested from the back of each animal.Half of the donor sites were treated with 120 mmHg negative pressure as the experimental group for 10 days and half were treated with vaseline gauze as the control.Changes in each wound were assessed every two days.Results The rate of re-epithelialization increased significantly.The donor sites healed after 4 to 6 days of negative pressure treatment, 2 to 4 days earlier than the control group.The level of inflammatory reaction occurring in wounds treated with negative pressure appeared less severe than that in wounds treated with vaseline gauze.Negative pressure could facilitate cell proliferation.The ratios of S,G2 and M phase increased significantly,and higher expression of PCNA was observed and detected in hair hollicle epithelium,regenerative basal cells and glandular epithelium on day 4 and 8 after negative pressure treatment.Conclusion Negative pressure could significantly increase the rate of skin donor site re-epithelialization

Objective To establish a kind of detection technique of nucleic acid based on surface plasmon resonance(SPR) and to set up the foundation of real-time, online space microbial detection. Methods A portable online bio-molecules analyzer based on SPR biosensor was applied. The probe was mercapto-modified at the 5’ end and immobilized on the sensor surface. Then the target sequences in the solution were monitored and sensitivity, specificity and reproducibility of the method were investigated. Results The results showed that detection method with good specificity and sensitivity could realize online detection of target sequence. The system could detect 2.3 nmol/L target sequence, CV value of nine detections was 3.5% and that of thirty detections was 14.7%. Conclusion The established nucleic acid detection method has the advantage of high sensitivity, good specificity and reproducibility, which can be applied in the field of nucleic acid detection.