A mechanical study on the bones of 29 rabbits following implantation of carbontendon was carried out. The rabbits were divided into seven groups according to the observation time (2,4,6,8,12,20 and 30 weeks after operation). A bundle of artificial tendon composed of 7,000 carbon fibers was passedthrough a tunnel in the tibia, and both ends of the artificial tendon were ligated to the muscle fibers. The mechanical strength and histological structure of the carbonbone junction and their relationship were studied in each group. Carbon fiberwas split and degradated in six to eight weeks after operation. The tensile strength of carbontendon in the soft tissue was decreased from 82±4.6N in the second week to 27±5.31N and6.3±1.81N in the sixth and eighth week respectively. The tensile strength of carbontendon increased from 3.01±1.2N to 6.1±2.01N at the carbon -tendon-bone junction in the bone. The tensile strength of carbon-tendon was unsatisfactory for implantation into bone. The carbon-tendon was split and degradated and the tensile strength was not b enough to cope with the early functional exercises.
The aim of this experiment was to study the osteogenesis in vivo of allogenic osteoblast combined culture with calcium phosphate composites. The osteoblasts were obtained by enzymatic digestion of periosteum from fibula subcultured to 13 generations, the cells were combined culture with hydroxyapatite and biphasic calcium phosphate. Subseguently, the composite was implanted into rabbits subcutaneously or intramuscularly. The blank material was implanted in the contralateral side as control. Four weeks later, all animals were sacrificed. All the implants were examined by gross observation, histological examination and EDXA. The results showed: 1. obvious ingrowth of connective tissue with very little inflammatory reaction; 2. new bone formation in the composites with deposit of Ca and P on the surface of osteoblast, but none in the blank materials; 3. no significant difference of new bone formation between the different sites of implantation or different materials, but those implanted intramuscularly had lamellae form of new bone while those implanted subcutaneously had only mineralization of extracellular matrix. The conclusion were: 1. the composites are biocompatible with prior osteogenesis property; 2. periosteal-derived allogenic osteoblasts obatined by enzymatic digestion could survive following implantation with bioactivity; 3. rich blood supply might be advantageous to new bone formation and its maturation.
In order to investigate the possibility of repairing injuried tendon with living artificial tendon, after combining culture, subcultured autogenous tendon cells with carbon fibers were implanted into the calcaneous tendon of rabbits. In different stages, the synthesis of type I collagen and their relevant morphological changes were observed. The results showed as follows: after implantation, tendon cells continued proliferating. Four weeks after implantation, tendon cells were detached from the carbon fibers and proliferated and produced collagen among the carbon fibers. The collagen fibrils were linked with each other to formed a dense structure. In the linkage site, the collagen fibrils originated from the implants joined to that from the ruptured end of the tendon, which meaned that the implant was healed with the recipient tendon. Observed under scanning electronic microscope, the tendon cells were lined among the carbon fibers evenly and in order, the collagen fibrils joined each other and formed an network, the fibrils were lined parallel to the carbon fibers. Under transparent electron microscope, the nucleolus were clear and organelle were abundant.
OBJECTIVE: To evaluate the clinical effect of drilling procedure following the hydroxyapatite orbital implantation. METHODS: From February 1996 to April 2000, 146 consecutive patients who received hydroxyapatite orbital implant were drilled and inserted a motility peg 6 to 16 months after hydroxyapatite implantation. Among them, there were 97 males and 49 females, aged from 18 to 60 years old, of the 146 motility pegs, 36 were sleeved pegs and 110 were nonsleeved. Goldman visual field analyzer was applied to measure the degree of artificial eye’s movement before and after drilling. RESULTS: Followed up for 1 to 40 months, no secondary infection occurred. The mobility of the prosthesis increased from (18.7 +/- 3.8) degrees preoperatively to (42.3 +/- 3.7) degrees postoperatively. CONCLUSION: The delayed drilling procedure and motility peg insertion improve the range of movement and the sensitivity of the artificial eye with a low rate of complications.
OBJECTIVE: To investigate the method and clinical effect of temporal fascia flap, free forearm flap, free iliac bone transfer and immediate implant on reconstruction of maxillary defect. METHODS: From February 1999 to July 2002, 8 cases of maxillary defects due to excision of cancer were repaired immediately with temporal fascia flap, free forearm flap, free iliac bone transfer and implant. Out of 8 patients, there were 6 males and 2 females, aged 32-49 years, with a disease course of 3 months to 2 years. RESULTS: Free iliac bone and forearm flap survived in all 8 cases. Osseo-integration could be seen and the implants could be used for denture repair and chew function. After 6-12 months, X-ray examination showed iliac bone healing; facial shape and functional restoration were satisfactory. CONCLUSION: Temporal fascia flap, free forearm flap, free iliac bone transfer and immediate implant is an ideal method to repair maxillary defect immediately and reconstruct its function.
Objective To observe the expression of related proteins of retina after subretinal implantation with inactive chips.Methods A total of 27 healthy adult New Zealand white rabbits were randomly divided into three groups: operation group (12 rabbits) in which the rabbits were implanted with inactive chips into the interspace beneath retina;shamoperation group (12 rabbits) in which the rabbits were implanted with inactive chips into the interspace beneath retina which was taken out immediately;the control group (3 rabbits). Animals were sacrified for immunohistological study 7,15,30 and 60 days after surgery.The rabbits in control group group were sacrified for immunohistological study after bred for 30 days.The expressions of glial fibrillary acidic protein (GFAP) and brain derived neurotrophic facor (BDNF) were observed.Results In operation group, the outer nulear layer of retina thinned, and the cells in the inner nulear layer was disorganized 7,15,and 30 days after the surgery;glial cells proliferated 60 days after surgery; the positive expression of BDNF and GFAP was more than that in the shamoperation and control group.In shamoperation group, the positive expression of BDNF and GFAP was more than that in the control group.No obvious difference of expression of BDNF and GFAP between each time point groups was found.Conclusions The expression of neroprotective related proteins increased after subretinal implantation with inactive chips suggests that limited neuroprotective effects might be led by the implantation.
To explore the histological and the hematological change of rabbits after implanting novel injectable artificial nucleus prostheses, and to evaluate the biological safety. Methods In accordance with Biological Evaluation of Medical Devices, materials of polyurethane, sil icone rubber and macromolecular polyethylene for medical use were made into short column 1 cm in length and 0.3 cm in diameter. Forty-eight SPF New Zealand white rabbits weighing 2.5-3.0 kg were used, and cavity 1 cm in depth was made in the area 2 cm away from the spinal midl ine by separating muscle.Then according to different material being implanted, the rabbits were divided into 3 groups (n=16): Group A, polyurethane; group B, sil icone rubber; group C, macromolecular polyethylene for medical use as negative control. General condition of the rabbits was observed after operation. Gross and histology observation were conducted 1, 4, 12 and 26 weeks after operation. Blood routine, biochemical function and electrolyte assays were performed 26 weeks after operation to observe pathological changes of organs. Meanwhile, physicochemical properties of the materials were detected, and the material in the same batch was used as negative control. Results All rabbits survived until the end of experiment, and all wounds healed by first intention. In each group, red swollen muscles were observed 1 week after operation and disappeared 4 weeks after operation, connective tissue around the implanted materials occurred 12 and 26 weeks after operation. At 26 weeks after operation, there were no significant differences among three groups in blood routine, biochemical function and electrolyte assays (P gt; 0.05). Organs had smooth surface without ulceration, ecchymosis, obvious swell ing, hyperemia or bleeding, and nodules. There were no significant differences among three groups in percentage weight of each organ (P gt; 0.05). Histology observation: granulation tissue prol iferation and inflammatory cell infiltration were observed in each group 1 week after operation, fibrous capsule formation around the materials and the disappearance of inflammatory cell infiltration were evident 4 weeks after operation, cyst wall grewover time and achieved stabil ity 12 weeks after operation. The inflammatory response and the fiber cyst cavity of groups A and B met the standard of GB/T 16175 and were in l ine with group C. No specific pathological changes were discovered in the organs 26 weeks after operation. For group A, no significant difference was evident between before and after material implantation in terms of weight average molecular weight, number average molecular weight, tensile strength at break and elongation at break (P gt; 0.05). For group B, no significant difference was evident between before and after material implantation in shore hardness (P gt; 0.05). Conclusion Novel injectable nucleus pulposus prostheses do not damage local tissue and function of organs, but provide good biocompatibil ity and biological safety.
Objective To investigate the biocompatibility of acellular urinary bladder submucosa (AUBS). Methods The acellular collagen matrix of human urinary bladder submucosa was developed using freeze-thawed enzymatic treatment and freeze-drying technique. Human oral keratinocytes were cultured and seeded on AUBS at a density of 2×106/ml in vitro.The proliferation of the cells were observed. Pockets were created in the abdominal muscle wall of 18 SD rats. AUBS in size 1 cm×1 cm was implanted into the pocket. The grafts were observed by light microscope 3, 6, 10, 14, 21 and 28 days after operation. Results AUBSmainly consisted of collagen fibers with a three-dimensional network structure. After the oral keratinocytes were seeded, continous oral epithelium layer was formed on the surface of AUBS after 10 days in vitro. Histological observation of the grafted AUBS showed progressive cell infiltration at 6 days. New capillaries formed at 14 days. The collagen fibers arranged regularly at 28 days after implantation. Conclusion Freeze-dried AUBS may be used as a suitable scaffold for tissue regeneration, which can induce cell proliferation both in vivo and in vitro and has good biocompatibilty.
ObjectiveTo systematically review the risk factors of related infections on the totally implantable venous access device (TIVAD) in adult.MethodsPubMed, EMbase, CINAHL, The Cochrane Library, CBM, WanFang Data, CNKI and VIP databases were electronically searched to collect case-control studies and cohort studies about the risk factors of TIVAD-related infections in adult from inception to April 2017. Two reviewers independently screened literature, extracted data and assessed the risk of bias of included studies, then, meta-analysis was performed by using RevMan 5.3 software.ResultsA total of one case-control study and 12 retrospective cohort studies involving 9 166 patients were included. The results of meta-analysis showed that: longer catheter utilization-days in the previous months (RR=1.06, 95%CI 1.02 to 1.10, P=0.001), inpatient treatment (RR=2.53, 95%CI 1.68 to 3.81, P<0.000 01), palliative care (RR=2.71, 95%CI 1.77 to 4.15,P<0.000 01), parenteral nutrition (RR=3.89, 95%CI 2.37 to 6.40,P<0.000 01), neutropenia (RR=2.20, 95%CI 1.30 to 3.72,P=0.003) and haematological malignancies (RR=3.54, 95%CI 2.03 to 6.17, P<0.000 01) were associated with increased risk of TIVAD-related infections in adult.ConclusionCurrent evidence shows that the risk factors of TIVAD-related infections include catheter utilization-days in the previous months, inpatient, palliative care, parenteral nutrition, neutropenia and hematological malignancies. Due to limited quality and quantity of the included studies, more high-quality studies are needed to verify conclusion.
Objective To evaluate the effect of the local del ivery of basic fibroblast growth factor 2 (bFGF-2) on the osseointegration around titanium implant of diabetic rats. Methods The bFGF-2-loaded poly (lactic-co-glycol ic acid) microspheres were prepared by water/oil/water (W/O/W) double-emulsion solvent evaporation method. Thirty-five male SPF level Sprague Dawley rats, weighing 220-250 g and aged 9 weeks, were selected as experimental animals. Ten rats were fedwith the routine diet as normal control group. The other 25 rats were made the diabetic animal model by giving high fat-sugar diet and a low dose streptozotocin (30 mg/ kg) intravenously; 20 rats were made the diabetic animal model successfully. Then 20 rats were randomly divided into diabetic control group (n=10) and bFGF-2 intervention group (n=10). A hole was drilled in the right tibia bone of all rats, and the titanium implant treated by micro-arc oxidation surface was planted into the hole. Simultaneously, the previously prepared microspheres and blood were mixed and were loaded on the surface of the implant before it was implanted into the rats of the bFGF-2 intervention group. At 4 and 8 weeks, the tibia containing implants was harvested, embedded with resin and made undecalcified tissue sl ices to compare the osseointegration. Results At 4 weeks, the implants of the normal control group were surrounded by new lamellar bone with continuity; whereas the tissue around the implants of the diabetic control group contained l ittle woven bone and some fibrous tissue; and obvious new formed bone with continuity was observed in bFGF-2 intervention group. At 8 weeks, the results of 3 groups were similar to those at 4 weeks. At 4 weeks, the percentage of bone-implant contact (BIC) in diabetic control group was significantly less than those in normal control group (P lt; 0.05) and in bFGF-2 intervention group (P lt; 0.05); the BIC in bFGF-2 intervention group was less than in normal control group, but showing no significant difference (P gt; 0.05). After 8 weeks, the BIC in normal control group and in bFGF-2 intervention group were significantly greater than that in diabetic control group (P lt; 0.05), but there was no significant difference between bFGF-2 intervention group and normal control group (P gt; 0.05). Conclusion Local del ivery of bFGF-2 around titanium implants may improve the osseointegration in diabetic rats.