Fabrication of Isoniazid/Rifampicin/Poly L-lactic Acid Donut-shaped Implants via Three Dimensional Printing Technique / 中国医学科学院学报

Objective To investigate the possibility of manufacturing dual-drug loaded isoniazid/rifampicin/poly L-lactic acid (PLLA) implant with donut-shaped structure via three-dimensional (3D) printing technique and study the drug release characteristic and biocompatibility of the implant in vitro.Methods PLLA was crushed into particles with diameters around 75-100 μm.Isoniazid and rifampicin bulk drugs were dissolved into the organic dissolvent respectively to be the binding liquid.The 3D printing machine fabricated the donut-shaped implant via binding the PLLA powder layer by layer.Dynamic socking method was used to study the in vitro release characteristics,and cell culture experiment was used to test the cytocompatibility of the implant.Results PLLA slow-release implants were made by using the PLLA powder as matrix and isoniazid/rifampicin organic solvent as binding liquid through 3D printing.The drugs in the implants distributed in nest under electron microscope.The concentrations of both drugs were still higher than the lowest effective bacteriostasis concentration after release for 32 days.Cytotoxicity and direct contact tests indicated that the implants had rare cytotoxicity and favorable biocompatibility. Conclusion The donut-shaped implants can be successfully fabricated using the 3D printing method,which offers a new method for the manufacturing of topical slow-release anti-tuberculosis drugs.

Versatility of reverse sural fasciocutaneous flap for reconstruction of distal lower limb soft tissue defects / 华中科技大学学报（医学）（英德文版）

In this study we present our experiences with the reverse sural fasciocutaneous flap to reconstruct the distal lower limb soft tissue defects caused by traumatic injuries. These flap graftings were carried out from Oct. 2010 to Dec. 2012 in our department. The series consisted of 36 patients, including 21 men and 15 women with an average age of 46.2 years (14-83 years) and with a medium follow-up period of 18 months (12-24 months). Of all the cases of acute trauma, there were 10 cases of trauma of distal tibia, 9 cases of trauma of perimalleolus, and 17 cases of trauma of midfoot and forefoot. Related risk factors in the patients were diabetes (2 cases), advanced age (>65 years, 3 cases) and cigarette smoking (6 cases). The reverse flow sural island flap irrigation depended on lower perforators of the peroneal artery. The fasciocutaneous pedicle was 3-4 cm in width and the anatomical structures consisted of the superficial and deep fascia, the sural nerve, short saphenous vein, superficial sural artery together with an islet of subcutaneous cellular tissue and skin. The most proximal border of the flap was only 1.5 cm away from the popliteal skin crease and the pivot point was 5-7 cm above the tip of the lateral malleolus. All the flaps survived. No arterial crisis occurred in any case. The venous congestion occurred in 2 cases and got better after raising the limbs and bloodletting. Only in an old man, 1.5 cm necrosis of distal margin of his flap occurred and finally healed after continuous dressing change. One-stage skin grafting was performed, and all the donor sites were sutured and successfully healed. It was concluded that the reverse sural fasciocutaneous flap is safe and reliable to extend to the proximal third even near the popliteal skin crease. We also concluded this flap can be safely and efficiently used to treat patients with large and far soft-tissue defects from the distal leg to the forefoot with more versatility and it is easier to reach the recipient sites.

Versatility of reverse sural fasciocutaneous flap for reconstruction of distal lower limb soft tissue defects / 华中科技大学学报（医学）（英德文版）

In this study we present our experiences with the reverse sural fasciocutaneous flap to reconstruct the distal lower limb soft tissue defects caused by traumatic injuries. These flap graftings were carried out from Oct. 2010 to Dec. 2012 in our department. The series consisted of 36 patients, including 21 men and 15 women with an average age of 46.2 years (14-83 years) and with a medium follow-up period of 18 months (12-24 months). Of all the cases of acute trauma, there were 10 cases of trauma of distal tibia, 9 cases of trauma of perimalleolus, and 17 cases of trauma of midfoot and forefoot. Related risk factors in the patients were diabetes (2 cases), advanced age (>65 years, 3 cases) and cigarette smoking (6 cases). The reverse flow sural island flap irrigation depended on lower perforators of the peroneal artery. The fasciocutaneous pedicle was 3-4 cm in width and the anatomical structures consisted of the superficial and deep fascia, the sural nerve, short saphenous vein, superficial sural artery together with an islet of subcutaneous cellular tissue and skin. The most proximal border of the flap was only 1.5 cm away from the popliteal skin crease and the pivot point was 5-7 cm above the tip of the lateral malleolus. All the flaps survived. No arterial crisis occurred in any case. The venous congestion occurred in 2 cases and got better after raising the limbs and bloodletting. Only in an old man, 1.5 cm necrosis of distal margin of his flap occurred and finally healed after continuous dressing change. One-stage skin grafting was performed, and all the donor sites were sutured and successfully healed. It was concluded that the reverse sural fasciocutaneous flap is safe and reliable to extend to the proximal third even near the popliteal skin crease. We also concluded this flap can be safely and efficiently used to treat patients with large and far soft-tissue defects from the distal leg to the forefoot with more versatility and it is easier to reach the recipient sites.

In vivo testing of canine prosthetic femoral components with HA-Ti ladder-type coating on vacuum plasma-sprayed Ti substrate / 华中科技大学学报（医学）（英德文版）

The purpose of the present study was to observe the structure and functional change of the bone-coating-prosthesis interface in vivo and to evaluate the histocompatibility of self-made prosthetic femoral components in the body and the degree of their bonding with the surrounding bone tissues as well as their stability. Six mature beagle dogs underwent bilateral hip replacement with prosthetic femur components. Three groups were established in terms of different coating of prothesis (four joints in each group): atmosphere (A) plasma-sprayed pure titanium (Ti) prosthetic joint with hydroxyapatite (HA) coating (HA+Ti+A group); vacuum (V) plasma-sprayed pure Ti prosthetic joint with HA coating (HA+Ti+V group); vacuum plasma-sprayed pure Ti prosthetic joint with Ti-HA stepped coating (Ti+HAG+Ti+V group). The hip joints were functionally evaluated, and subjected to X-ray examination, biomechanics inspection, and histological examination. As a result, X-ray imaging revealed all prosthetic joints were in a good location and no dislocation of joint was found. Shear strength of interface was significantly higher in Ti+HAG+Ti+V group than in HA+Ti+V group (P<0.05) and HA+Ti+A group (P<0.05) at 28th week. Histological examination showed the amount of newborn bone in Ti+HAG+Ti+V group was more than in HA+Ti+V group and HA+Ti+A group after 28 weeks. It was suggested that vacuum plasma-sprayed pure Ti prosthetic joint with TI-HA stepped coating could improve the bonding capacity of bone-prosthesis, enhance the stability of prosthesis, and increase the fixion of prosthetic femoral components because of better bone growth. This new type of biological material in prosthetic femoral components holds promises for application in clinical practice.

Clinical analysis of 73 cases of intraspinal nerve sheath tumor / 华中科技大学学报（医学）（英德文版）

Seventy-three patients with spinal nerve sheath tumor who were surgically treated in our hospital during the years 2004-2010 were retrospectively reviewed with respect to recovery of neurological function, recurrence of the tumor and occurrence of kyphotic deformities. Preoperative clinical manifestations, imaging data, surgical records and follow-up results were comprehensively analyzed. The follow-up duration was 12-60 months with an average of 32.0 months. Out of the 73 cases enrolled, 69 had gradual recovery of sensation, motor and sphincter functions 1 week to 3 months after operation. Forty-six cases had incomplete paralysis, whose American Spinal Injury Association (ASIA) grades, however, were gradually increased during the follow-up period, 4 cases had no significant improvement of the clinical symptoms and no change in ASIA grades during the follow-up period. Two cases had postoperative recurrence of the tumor. There were no deaths, no spinal instability, and no kyphotic malformations found in any cases. Our study indicated that complete removal of the tumor is important for good recovery, and an ideal surgical method may reduce the recurrence of the tumor or the occurrence of complications.

In vivo testing of canine prosthetic femoral components with HA-Ti ladder-type coating on vacuum plasma-sprayed Ti substrate / 华中科技大学学报（医学）（英德文版）

The purpose of the present study was to observe the structure and functional change of the bone-coating-prosthesis interface in vivo and to evaluate the histocompatibility of self-made prosthetic femoral components in the body and the degree of their bonding with the surrounding bone tissues as well as their stability. Six mature beagle dogs underwent bilateral hip replacement with prosthetic femur components. Three groups were established in terms of different coating of prothesis (four joints in each group): atmosphere (A) plasma-sprayed pure titanium (Ti) prosthetic joint with hydroxyapatite (HA) coating (HA+Ti+A group); vacuum (V) plasma-sprayed pure Ti prosthetic joint with HA coating (HA+Ti+V group); vacuum plasma-sprayed pure Ti prosthetic joint with Ti-HA stepped coating (Ti+HAG+Ti+V group). The hip joints were functionally evaluated, and subjected to X-ray examination, biomechanics inspection, and histological examination. As a result, X-ray imaging revealed all prosthetic joints were in a good location and no dislocation of joint was found. Shear strength of interface was significantly higher in Ti+HAG+Ti+V group than in HA+Ti+V group (P<0.05) and HA+Ti+A group (P<0.05) at 28th week. Histological examination showed the amount of newborn bone in Ti+HAG+Ti+V group was more than in HA+Ti+V group and HA+Ti+A group after 28 weeks. It was suggested that vacuum plasma-sprayed pure Ti prosthetic joint with TI-HA stepped coating could improve the bonding capacity of bone-prosthesis, enhance the stability of prosthesis, and increase the fixion of prosthetic femoral components because of better bone growth. This new type of biological material in prosthetic femoral components holds promises for application in clinical practice.

Clinical analysis of 73 cases of intraspinal nerve sheath tumor / 华中科技大学学报（医学）（英德文版）

Seventy-three patients with spinal nerve sheath tumor who were surgically treated in our hospital during the years 2004-2010 were retrospectively reviewed with respect to recovery of neurological function, recurrence of the tumor and occurrence of kyphotic deformities. Preoperative clinical manifestations, imaging data, surgical records and follow-up results were comprehensively analyzed. The follow-up duration was 12-60 months with an average of 32.0 months. Out of the 73 cases enrolled, 69 had gradual recovery of sensation, motor and sphincter functions 1 week to 3 months after operation. Forty-six cases had incomplete paralysis, whose American Spinal Injury Association (ASIA) grades, however, were gradually increased during the follow-up period, 4 cases had no significant improvement of the clinical symptoms and no change in ASIA grades during the follow-up period. Two cases had postoperative recurrence of the tumor. There were no deaths, no spinal instability, and no kyphotic malformations found in any cases. Our study indicated that complete removal of the tumor is important for good recovery, and an ideal surgical method may reduce the recurrence of the tumor or the occurrence of complications.

Adhesion, proliferation and osteodifferentiation of bone mesenchymal stem cells on PLGA-ASP-PEG tri-bolck polymer scaffolds / 中国骨伤

<p><b>OBJECTIVE</b>To explore the adhesion,proliferation and osteodifferentiation of bone mesenchymal stem cells (BMSCs)on the prepared lactic acid/glycolic acid/asparagic acid-co-polyethylene glycol(PLGA-[ASP-PEG])tri-block polymer scaffolds.</p><p><b>METHODS</b>Modified PLGA with polyethylene glycol (PEG) and asparagic acid(ASP)that has many liga nds,and then the synthesis PLGA-[ASP-PEG] tri-block polymer material was prepared. BMSCs were cultured in PLGA-[ASP-PEG] polymer material and poly lactic acid-co-glycolic acid(PLGA)were used as control group. Precipitation method, MUT assay and total cellular protein detection were used to test the adhersion and proliferation of BMSCs. After the third generation of BMSCs was cultured on PLGA-[ASP-PEG] tri-block polymer scaffolds for 14 day and 28 day with osteogenic supplements,the osteodifferentiation of MSCs were observed through alkaline phosphatase(ALP) staining and calcium tubercle staining.</p><p><b>RESULTS</b>BMSCs grew adherent to the surface of PLGA-[ASP-PEG] polymer scaffolds and the number of BMSCs was much higher than that of PLGA. The precipitation method suggested that adhesion and proliferation of BMSCs on the surface of PLGA-[ASP-PEG] was much higher than the control group (P < 0.05). MTU assay showed that after BMSCs were cultured for 20 days,the absorbance A of PLGA-[ASP-PEG] polymer scaffolds and PLGA were 1.336 and 0.780 respectively. Total cellular protein could image the adhersion and proliferation of BMSCs indirectly. After BMSCs were cultured for 12 days,the total cellular protein of PLGA-[ASP-PEG] and PLGA were 66.44 microg/pore and 41.23 microg/pore respectively. PLGA-[ASP-PEG] polymer scaffolds had well biocompatibility and cell adhersion. The positive results with ALP staining and calcium tubercle staining in both groups indicated tri-block polymer scaffold and its degradations had no effect on osteodifferentiation.</p><p><b>CONCLUSION</b>PLGA-[ASP-PEG]could improve the adhesion and proliferation of seed cells on bone-matrixmaterial, maintain the morphous of seed cells and had no obvious effect on cell osteodifferentiation.</p>

Adhesion and Proliferation of Bone Mesenchymal Stem Cells with PLGA-[ASP-PEG] Polymer Scaffolds / 中国生物工程杂志

Objectives: To investigate the effects of adhesion and proliferation of bone mesenchymal stem cells (BMSCs) in the surface of lactic acid/glycolic acid/asparagic acid-co-polyethylene glycol PLGA-[ASP-PEG] tri-block polymer scaffolds, try to find a new biomaterial to induce seed cells in vitro for bone tissue engineering. Methods: Modified PLGA with polyethylene glycol (PEG) and asparagic acid (ASP) that has many ligands, and synthesis PLGA-[ASP-PEG] polymer material. BMSCs were cultured in PLGA-[ASP-PEG] polymer material and PLGA used as control group. Through precipitation method, MTT assay and total cellular protein detection to test the adhersion and proliferation of BMSCs. Scanning electron microscope is used to observe cells appearance. Results: BMSCs on the surface of PLGA-[ASP-PEG] polymer scaffolds are adherention to the culture flask, the number of cells is much higher than PLGA’s. The precipitation method suggest that adhesion and proliferation of BMSCs on the surface of PLGA-[ASP-PEG] is much higher than the control group(P

Bone Marrow Mesenchymal Stem Cells Express Neurotrophic Factores and Protect Neural Stem Cells / 中国康复理论与实践

@#ObjectiveTo investigate bone marrow mesenchymal stem cells(BMSC) express brain derived neurotrophic factor(BDNF) and nerve growth factor(NGF) and their protective effect for neural stem cells (NSCs).MethodsBMSC were obtained from rat tibiae and femurs and centrifuged with Ficoll. The passage 3 cells were chosen to make immunocytochemical stain for CD44, CD71 and CD45. The expression of BDNF and NGF was detected in BMSC with RT-PCR, as well as in the media with ELISA. The media that cultured BMSC were collected as BMSC condition media. NSCs were obtained from cerebral cortex of new-born rat and cultured in vitro. After different ratio of BMSC condition midia were added, NSCs were induced to apoptosis with heat-shock, then NSCs were dyed with Annexin V-FITC/PI apoptosis kit and apoptosis rates were tested with flow cytometry. ResultsBMSC were CD44(+), CD45(-), CD71(+) and expressed BDNF and NGF mRNA. BDNF and NGF could be tested in the media of cultured BMSC and increase with cultured time. BMSC condition media could reduce the ratio of heat-induced apoptosis of NSCs, and more BMSC condition media showed better effect. ConclusionBMSC can express neurotrophic factores and protect neural stem cells from heat-induced apoptosis.

Effects of type I collagen on adhesion,proliferation and osteogenic differentiation of rabbit bone marrow stromai cells on PLGA-[ASP-PEG]scaffolds / 中华创伤骨科杂志

Objective To explore the effects of surface modification of PLGA-[ASP-PEG] scaffold with typeⅠcollagen on the adhesion,proliferation and osteogenic differentiation of rabbit bone marrow stromal cells (BMSCs).Methods After PLGA-[ASP-PEG] materials were modified with typeⅠcollagen chemically,the collagen was coated onto the materials physically.The BMSCs obtained from rabbits were cultured on the modified PLGA-[ ASP-PEG] and on the unmodified PLGA-[ ASP-PEG] as control.The adhesion and proliferation behavior of the cells was analyzed and the expressions of osteogenie marker alkaline phosphatase,osteocalcin,osteopontin,typeⅠcollagen and core binding factor al were also detected.Results X-ray photoelectron spectrometry(XPS) confirmed that TypeⅠcollagen was grafted onto the surface of PLGA-[ASP-PEG] successfully and the collagen content on the materials modified chemically and physically was significantly increased.The abilities of adhesion and proliferation and the expressions of osteogenie makers of the BMSCs were significantly greater than those in the control group(P＜0.05).Conclusion Since Type collagen I can improve the biocompatibility of PLGA- [ASP-PEG] scaffold materials,it can be used as a new way to optimize scaffolds in tissue engineering.

Effects of TGF beta1 autocrine blockage on osteosarcoma cells / 中国医学科学杂志(英文版)

<p><b>OBJECTIVE</b>To evaluate the effects of transforming growth factor beta1 (TGFbeta1) autocrine blockage on proliferation activity and drug sensitivity of osteosarcoma. METHODS; Northern blot, MTT determination, and 3H thymidine incorporation were used to investigate the effects of antisense TGF beta1 gene on osteosarcoma.</p><p><b>RESULTS</b>The proliferation of osteosarcoma cells transfected by antisense TGF beta1 gene was suppressed markedly, and adriamycin sensitivity was significantly increased.</p><p><b>CONCLUSION</b>Blockage of osteosarcoma cells TGF beta1 autocrine loop inhibits cell proliferation and enhances chemotherapy sensitivity.</p>

Effects of basic fibroblast growth factor on biological characteristics of osteoblasts / 中华创伤杂志(英文版)

<p><b>OBJECTIVE</b>To elucidate the effects of exogenous basic fibroblast growth factor (bFGF) on biological characteristics of rat osteoblasts cultured in vitro.</p><p><b>METHODS</b>The osteoblasts isolated from a Sprague-Dawley rat and cultured in vitro were treated with different concentrations of bFGF (5-50 ng/ml) respectively. At 24 hours after treatment, the proliferating cell nuclear antigen was measured with immunocytochemistry, alkaline phosphatase (ALP) activity was determined and the expression of transforming growth factor beta 1 (TGF-beta(1)) was detected to observe the effects of bFGF on growth and differentiation of osteoblasts.</p><p><b>RESULTS</b>bFGF (5-50 ng/ml) could obviously promote the growth of osteoblasts. The intracellular expression of TGF-beta(1) mRNA increased significantly, but the intracellular ALP content decreased.</p><p><b>CONCLUSIONS</b>bFGF can obviously stimulate the proliferation of osteoblasts and promote the synthesis of TGF-beta(1), but cannot promote the differentiation of osteoblasts.</p>