The interaction of biomaterials and tissues has been the focus of biomaterial science for many years and formed the foundation of the subject of biocompatibility. The research about biomaterials provides better basis for biomedical devices by the understanding of biocompatibility phenomena. In this paper, over 50 years of experience with such devices is analysed and it is shown that, in the vast majority of circumstances, the sole requirement for biocompatibility in a medical device intended for long-term contact with the tissues of the human body is that no harm should be brought to those tissues. Only a few bio-active biomaterials has been applied successfully in clinics. This artical gives a review on the application of biomaterials in tissue engineering,sophisticated cells, drug and gene delivery systems and in biotechnology. Interactions between biomaterials and tissue components is discussed as well.

BACKGROUND: In according to ISO-10993-4 and GB/T 16886.4, the in vitro hemo-compatibility evaluation on biomaterieisincludes thrombosis, coagulation factors, platelets and platelet functions, hematology and complement system. However, in thecase of China, the in vitro hemo-compatibility evaluations were performed only thrombosis, coagulation factors and plateletattachment, the investigation on evaluation of platelet and complement activations is less reported.OBJECTIVE: To evaluate the effect of polyethylene, polyvinyl chloride and polymethylvinylsiloxane tubes on platelet activation,and establish a useful method to evaluate the effect of tubular materials on platelet activation.METHODS: Tubes of polyethylene, poiyvinyl chlorid and silastic were established by 3.7 mm inner diameter, 3.5 mm externaldiameter, and 35 cm length, respectively. 1 mL blood was injected into the tube of polyethylene, polyvinyl chlorid and silasUc,respectively. The tubes were connected using a two-way tube, shaken at 140 r/min by 30° sloping for 3.5 hours at 37 ℃.Radiolmmunoassay was employed to detect α-granules protein level of platelet poor plasma, while flow cytometry was used todetect the percentage of positive plateiet of o-granules protein and that of activated gp Ⅱb/Ⅲa composite.RESULTS AND CONCLUSION: Radiolmmunoassay showed that o-granules protein level of plateiet poor plasma in thepolyethylene and polyvinyl chlorid tubes was significantly greater than that in the silastic tube (P < 0.05). There were no significantdifferences in o-granules protein between polyethylene and polyvinyl chlorid (P > 0.05). Flow cytometry indicated that percentageof positive platelet of o-granules protein in the polyethylene and polyvinyl chlorid tubes was significantly greater than that in thesilastic tube (P < 0.05); the percentage in the polyethylene tube was significantly greater than that in the polyvinyl chlorid tube (P <0.05). There was no significant differences in the percentage of positive plateiet of activated gp IIb/IIIa composite between thethree materials (P > 0.05). A useful blood-material contact model was established, and it was considered that o-granules protein isan available parameter for evaluating platelet activation. The percentage of positive platelet of o-granules protein determined byflow cytometry was a more sensitive parameter for evaluating platelet activation.

BACKGROUND:In recent years, bacterial celulose modified by nano-composite technology has been endowed with new properties. OBJECTIVE:To review the combination of bacterial celulose and nanosilver to prepare wound dressing. METHODS: A computer-online search was performed in PubMed (2013-01/2015-04) and CNKI (2007-01/2015-04) databases to retrieve studies on bacterial celulose, nanosilver and their compound method and application using the key words of “bacterial celulose, nano-silver” in English and Chinese, respectively. RESULTS AND CONCLUSION:Bacterial celulose/nano-silver compound can be prepared by three methods: solution impregnation, in situ composite and biocomposite. Solution impregnation method can lower the concentration of nanosilver ions in the fiber matrix to highly control the release of silver ions, but the genetic toxicity and biocompatibility are unclear.In situcomposite method can reduce the damage to the mesh structure of celulose on which silver ions can be bonded firmly to reduce the toxic damage to cels, but the reducing agent used has a higher toxicity, which is difficult to remove. Biocomposite method cannot produce toxic substance, which is friendly to the environment, and the synthetic biomaterials have less harm to the human body and can be controled highly.

Objective To compare biocompatibility and safety of six implantation prosthesis. Methods Subcutaneous implantation of crosslinked sodium hyaluronate prosthesis (CSHP), silica gel prosthesis(SGP), non crosslinked sodium hyalurorate prosthesis (NCSHP), carboxy methycel prosthesis (CMCP), hydrophilic polyacrylamide gel prosthesis (HPAGP), injectable hydrophilic polyacrylamide gel (IHPAG) was performed in 12 beagle dogs.Local reaction of surrounding tissues of the transplants were observed with HE and Van Gieson stains after the transplantation at 14, 30 and 90 days, 6 months, and 1 and 2 years. Results The most serious reaction was observed in NCSHP, CMCP and HPAGP, moderate reaction in CSHP and SGP and mild reaction in IHPAG. Van Gieson staining showed that collagenous fibrous capsule around implanted prosthesis was formed from 30 days to 2 years .The component and arrangment of the capsule were different among the defferent prosthesis, but changed with time. Shrinkage of the capsules was found in NCSHP, CMCP and HPAGP, and contraction occurred two years later. The capsules formed by CSHP and SGP had no contraction after two year implantation. IHPAG capsule was still soft and elastic after 2 years. Conclusions SGP is one of the best material for breast enlargement with a good biocompatobility and soft capsule. IHPAG is a new filling material with mild inflammatory reaction and thinner and softer capsule. CSHP should be improved further because its molding effect is not gratified. Both the biocompatibility and molding effect of NCSHP, CMCP and HPAGP are not gratified and further modification is needed.

Objective To explore the effect of immunogenicity of freeze-dried bone allograft on different in vitro experimental models. Methods The lymphocytes were obtained respectively from 10 healthy young human volunteers, 10 Balb/c and 10 C57 mice and 10 New Zealand rabbits. The experiment was carried out in 6 groups: positive control group (PHA/ConA+lymphocyte), negative control group (Hydroxyapatite powder + lymphocyte), allogeneic bone group A (Freeze-dried bone powder 2. 0 g/L + lym-phocyte), allogeneic bone group B (Freeze-dried bone powder 1.0 g/L + lymphocyte), allogeneic bone group C (Freeze-dried bone powder 0.5 g/L + lymphocyte), and negative control group (culture solution + lym-phocyte). Lymphocyte transformation test (Alamarblue) was conducted to culture the 6 kinds of experimental materials in vitro. After 72 hours, samples were scanned with ELISA muhiscan at wave lengths 570 nm and 600 nm to fetal the light absorption value. Pearson analyses were performed 10 determine the relationships a-mong the 3 animals and 1 human groups and find out which animal would be highly correlated to human. Results In the human and Balb/c mice lymphocyte transformation tests, there was no significant difference (P > 0.05) between allogeneic bone groups A, B, C and negative control group (HA) ; but there was sig-nificant difference (P < 0.001) between allogeneic bone groups A, B, C and positive control group (PHA/ConA); there was no significant difference between the 3 allogeneic bone groups (P > 0.05). There was no significant difference among the 6 groups of C57 mice and New Zealand rabbits (P > 0.05). The coefficient r between Balb/c mice and human groups was 0.959, P = 0.003, showing a highly positive correlation. The coefficient r between C57 mice and human groups was 0.527, P = 0.283, while the coefficient r between New Zealand rabbits and human groups was 0.866, P =0.026. Conclusions The immunogenicity of freeze-dried bone powder in this experiment may not be sufficient enough to induce significanrt immunologic response. Balb/c mice may be preferable for immunogenicity related experiments.

BACKGROUND: A mass of unknown remains are founded in sodium hyaluronate product when it was tested for quality control. OBJECTIVE: To qualify and quantify unknown residual solvents of sodium hyaluronate product and determine hazardsaccording to standard toxicological data. DESIGN, TIME AND SETTING: A quality and quantity study with combined gas chromatography mass spectrometry was performed at National Institute for the Control of Pharmaceutical and Biological Products from May to June 2007.MATERIALS: Experimental samples were spot-checked, and purified water was also used.METHODS: The samples were qualified and quantified using combined gas chromatography mass spectrometry.MAIN OUTCOME MEASURES: Methanol, xylene and ethyl benzene were qualified and quantified.RESULTS: Combined gas chromatography mass spectrometry demonstrated that residual solvents in the sodium hyaluronateproducts were methanol, xylene, and ethyl benzene. The quantization of methanol was 414.365 μg/mL, the quantization of o-xylene was 0.19 μg/mL, and the quantization of ethyl benzene was 0.22 μg/mL. CONCLUSION: Methanol, xylene, and ethyl benzene were firstly identified as residual solvents in sodium hyaluronate products. Besides, we discussed methods of qualifying and quantifying these three residual solvents.

BACKGROUND: It has been reported that nanosilver-containing biomaterials produce bad biological effects after they directly contact with or are implanted into human body.OBJECTIVE: To investigate whether nanosilver yields potential adverse biological effects on human body and to evaluate its bioiogical safety.DESIGN, TIME AND SETTING: An animal experiment observation was performed at the Medical Device Center of National Institute for the Control of Pharmaceutical and Biological Products from June 2005 to August 2006.MATERIALS: Nanosilver particles and microsilver particles were purchased from Sigma Company, USA.METHODS: Thirty rats were randomly divided into 3 groups, with 5 male and 5 female rats per group: nanosilver, microsilver, and blank control. Nanosilver and microsilver particles were respectively and subcutaneously implanted for subchronic toxicity test.The nanosilver and microsilver groups were given 0.33 g/kg nanosilver and microsilver, respectively. Rats from the blank control group received identical procedure, with the exception of drug application. Four rats were selected from each group for determination of silver content in serum and some organs by plasma mass spectrometry.MAIN OUTCOME MEASURES: serum biochemical indices, organ coefficient, and silver content.RESULTS: There was significant difference in individual organ coefficient between each drug application group and blank control group. But no significant difference in absolute mass was found between each drug application and the blank control group.These findings suggested no clinical significance of organ coefficient. Other organ coefficients were in the normal range, and there was no significant difference between each drug application group and the blank control group. Patho-histological changes related to toxicity were not found. Rats from the nanosilver group did not show toxic reaction.CONCLUSION: Nanosilver produces potential adverse biological effects after implanted into human body.

The aim of this research was to evaluate the influence of steam sterilization on poly(ethylene glycol-terephthalate) and poly(butylene terephthalate) copolymer (PEGT/PBT) and its vascular cells compatibility, which was used as the scaffolds in vascular tissue engineering. Endothelial cells, smooth muscle cells and fibroblasts were cultured separately on the films after steam sterilization and after ultraviolet sterilization. These cells can grow well on the films after ultraviolet sterilization, while they can hardly adhere on steam sterilized films. Differential scanning calorimetry, static contact angle, X-ray photoelectron spectroscopy, surface carboxyl density quantity, H-nuclear magnetic resonance and scanning electronic microscope were employed to characterize the properties of poly(ether-esters) films before and after sterilization. These results showed that steam sterilization had little effect on the surface morphology and on the constitution of the copolymer, but the copolymer segments were redistributed during steam sterilization. The hydrophilic poly(ethylene glycol) (PEG) and the end carboxyl groups transferred from the bulk and enriched on the surface and the degree of crystallinity of hard segments increased slightly. Both the end carboxyl and PEG enriched on the surface can hinder the protein adhesion on the surface; so, lacking in receptor, the vascular cells cannot adhere on the films surfaces.
Biocompatible Materials ; chemistry ; Cell Adhesion ; Endothelial Cells ; cytology ; Humans ; Polyesters ; chemistry ; Polyethylene Glycols ; chemistry ; Polyethylene Terephthalates ; chemistry ; Steam ; Sterilization ; Surface Properties ; Umbilical Veins ; cytology

There has been increasing attention over the past few years on the potential for the medical devices to cause changes in the immune systems, and it was necessary to provide guidance on how to address the adverse effects of medical devices on the immune system. Here we introduce the principles and methods for immunotoxicology testing of medical devices.
Biocompatible Materials ; Equipment and Supplies ; adverse effects ; standards ; Humans ; Immune System Diseases ; etiology ; Materials Testing ; methods ; standards ; Prostheses and Implants ; adverse effects ; Toxicity Tests ; methods

In-vitro test is usually conducted as a preliminary screening test in the evaluation of the haemocompatibility of biomaterials for its short-term consuming, convenience and less expense. The selection of appropriate model for blood-biomaterial interaction, the choice of sensitive and specific parameters, and the minimization of additional blood activation are most important in the in-vitro test. In addition, the time and the style of blood-biomaterial interaction, the choice of sensitive and specific parameters, and the minimization of additional blood activation are most important in the in-vitro test. In addition, the time and the style of blood-biomaterial interaction, the selection of primary reference materials and the shear rate should be considered. In recent years, though great progress has been made in the in-vitro evaluation of haemocompatibility of biomaterials, all these influencing factor should be standardized for more effective evaluation of the haemocompatibility of biomaterials.
Biocompatible Materials ; Evaluation Studies as Topic ; Humans ; Materials Testing ; standards