INTRODUCTIONThe risk of surgery-related infection is a persistent problem in orthopaedics and infections involving implants are particularly difficult to treat. This study explored the responses of bone and soft tissue to antimicrobial-coated screws. We investigated whether such screws, which have never been used to fix bony tissues, would result in a cytotoxic effect. We hypothesised that the coated screws would not be toxic to the bone and that the likelihood of infection would be reduced since bacteria are not able to grow on these screws.

METHODSTitanium screws were inserted into the left supracondylar femoral regions of 16 rabbits. The screws were either uncoated (control group, n = 8) or coated with a polyvinylpyrrolidone-polyurethane interpolymer with tertiary amine functional groups (experimental group, n = 8). At Week 6, histological samples were obtained and examined. The presence of necrosis, fibrosis and inflammation in the bony tissue and the tissue surrounding the screws was recorded.

RESULTSLive, cellular bone marrow was present in all the rabbits from the experimental group, but was replaced with connective tissue in four rabbits from the control group. Eight rabbits from the control group and two rabbits from the experimental group had necrosis in fatty bone marrow. Inflammation was observed in one rabbit from the experimental group and five rabbits from the control group.

CONCLUSIONTitanium surgical screws coated with polyvinylpyrrolidone-polyurethane interpolymer were associated with less necrosis than standard uncoated screws. The coated screws were also not associated with any cytotoxic side effect.

Animals ; Bone Screws ; Coated Materials, Biocompatible ; Polyurethanes ; toxicity ; Povidone ; toxicity ; Rabbits ; Surgical Wound Infection ; prevention & control ; Titanium

Nowadays, nanotechnologies have shown wide application foreground in the biomedical field of medicine laboratory tests, drug delivery, gene therapy and bioremediation. However, in recent years, nanomaterials have been labeled poisonous, because of the disputes and misunderstandings of mainstream views on their safety. Besides, for the barriers of technical issues in preparation like: (1) low efficacy (poor PK & PD and low drug loading), (2) high cost (irreproducibility and difficulty in scale up), little of that research has been successfully translated into commercial products. Currently, along with the new theory of "physical damage is the origin of nanotoxicity", biodegradability and biocompatibility of nanomaterials are listed as the basic principle of safe application of nanomaterials. Combining scientific design based on molecular level with precision control of process engineering will provide a new strategy to overcome the core technical challenges. New turning point of translational medicine in nanotechnology may emerge.
Biocompatible Materials ; Nanostructures ; toxicity ; Nanotechnology ; Translational Medical Research

OBJECTIVEThe biological safety of a new developed silicone rubber for inflatable silastic prosthesis (SRISP) was evaluated.

METHODSFollowing the GB/T 16886.10-2005 standard, YY/T 0127.13-2009 standard, and GB/T 16886.11- 2011 standard, samples were prepared and tested by animal experiments, such as guinea pig maximization test, oral mucous membrane irritation test, and short-term systemic toxicity test (oral route).

RESULTSNo obvious erythema and edema in the guinea pig abdominal skin were observed after 24, 48, and 72 h of stimulating touch, thus indicating that SRISP does not cause potential skin sensitivity. No local response to SRISP was found, and the visual observation and pathological findings of oral mucosa were normal and similar to that of the control group. Therefore, SRISP had no irritation response to oral mucosa. No clinical signs of toxicity were observed in rats, and no significant differences in weight and weight relative growth rate between extract group and blank control group (P > 0.05) were found. Thus, SRISP had no short-term systemic toxicity.

CONCLUSIONThese results indicated that SRISP met the requirement of biomedical materials and had good bio- security.

Animals ; Biocompatible Materials ; Cosmetics ; Dimethylpolysiloxanes ; Guinea Pigs ; Prostheses and Implants ; Rats ; Silicone Elastomers ; Toxicity Tests

This study evaluated the cytotoxicity of a new type silicone rubber for maxillofacial prosthesis, which was developed by the present authors. According to the GB/T16886. 5- 2003, the samples were prepared and tested with cell counting kit-8 (CCK-8) assay, the relative growth rate (RGR) was calculated, and morphology of L929 cells were observed by scanning electron microscope and phase contrast microscope. The results showed that RGR of L929 cells were 91.65% (24 h), 87.03% (48 h), 87.30% (72 h), respectively, and the level of cytotoxicity was grade 1. The L929 cells showed typical fusiform shape and their morphology did not changed significantly after 24 h, 48 h and 72 h. These data indicated that the newly-developed silicone rubber material, as a maxillofacial prosthesis material, should be a safe biomaterial.
Animals ; Biocompatible Materials ; Cell Line ; Humans ; Maxillofacial Prosthesis ; Mice ; Silicone Elastomers ; toxicity

We examined the biocompatibility and the safety of a-calcium sulfate hemihydrate (CSH)/multi-walled carbon nanotube (MWCNT) composites for bone reconstruction application. The biocompatibility of the CSH/MWCNT composites was evaluated by the measures which taking L929 fibroblast cells cultured in the extracted liquid of the composite soaking solution and putting bone marrow stromal cells planted on the composite pellets in vitro, respectively. The cell proliferation was evaluated by MTT test and further observed using an inverted optical microscope and a scanning electric microscope. The toxicity of the composites was evaluated by acute and subacute systemic toxicity test. Long-term muscle and bone implantation in vivo tests were also conducted. L929 fibroblast cells grew well in the extracted liquid, as well as bone marrow stromal cells that could adhere on the surface of sample pellets and proliferated rapidly. MTT test showed that there were no significant differences between the experimental and control groups (P > 0.05). In vivo test manifested that the composites were no toxicity, no irritation to skin and good for bone defect reconstruction. It was proved that a-calcium sulfate hemihydrate (CSH)/multi-walled carbon nanotube (MWCNT) composites exhibited excellent biocompatibility for the potential application in bone tissue engineering.
Animals ; Biocompatible Materials ; chemistry ; Bone Marrow Cells ; cytology ; Bone Substitutes ; chemical synthesis ; chemistry ; Calcium Sulfate ; chemistry ; Cell Line ; Cell Proliferation ; Fibroblasts ; cytology ; Materials Testing ; Nanotubes, Carbon ; chemistry ; Rabbits ; Stromal Cells ; cytology ; Tissue Engineering ; methods ; Toxicity Tests

Hyaluronan acid sodium gels are used in ophthalmic surgery, orthopedic treatment and cosmetic surgery. In 2009,there were 12 domestic manufacturers in China producing 33 kinds of products. 23 kinds of imported products were allowed by SFDA to sale in the meantime. Since manufacturers use different production processes, product performances are quite different. According to the GB/T 16886. 1-2001, we designed a pilot program to evaluate the sodium hyaluronate gel products comprehensively in this paper. The results showed that, except chromosome aberration test of gel A and subchronic systemic toxicity of gel C appeared positive, the remaining samples of the test results were negative. This article provides a reference to write standard of cross-linked hyaluronic sodium gel and the revision of standard YY0308-2004.
Animals ; Biocompatible Materials ; standards ; Cross-Linking Reagents ; chemistry ; Gels ; Hyaluronic Acid ; standards ; Mice ; Pilot Projects ; Quality Control ; Rabbits ; Rats ; Rats, Sprague-Dawley ; Toxicity Tests ; methods

Graphene is a kind of atomic crystal with two-dimensional polycyclic aromatic hydrocarbons planes, which is of great concern in various fields. This paper reviews the latest development of graphene-based materials in biomedical research fields in the recent years, including in vitro and in vivo toxicity, drug loading, targeting controlled release, as well as photodynamic therapy. These researches validate that the graphene-based materials indicate promising prospects in the application to biomedicine.
Animals ; Biocompatible Materials ; Drug Carriers ; Graphite ; chemistry ; therapeutic use ; toxicity ; Humans ; Nanoparticles ; Neoplasms ; therapy ; Oxides ; chemistry ; therapeutic use ; toxicity ; Photochemical Processes ; Phototherapy ; methods

AIMTissue engineering is a promising area with a broad range of applications in the fields of regenerative medicine and human health. The emergence of periodontal tissue engineering for clinical treatment of periodontal disease has opened a new therapeutic avenue. The choice of scaffold is crucial. This study was conducted to prepare zein scaffold and explore the suitability of zein and Shuanghuangbu for periodontal tissue engineering.

METHODOLOGYA zein scaffold was made using the solvent casting/particulate leaching method with sodium chloride (NaCl) particles as the porogen. The physical properties of the zein scaffold were evaluated by observing its shape and determining its pore structure and porosity. Cytotoxicity testing of the scaffold was carried out via in vitro cell culture experiments, including a liquid extraction experiment and the direct contact assay. Also, the Chinese medicine Shuanghuangbu, as a growth factor, was diluted by scaffold extract into different concentrations. This Shuanghuangbu-scaffold extract was then added to periodontal ligament cells (PDLCs) in order to determine its effect on cell proliferation.

RESULTSThe zein scaffold displayed a sponge-like structure with a high porosity and sufficient thickness. The porosity and pore size of the zein scaffold can be controlled by changing the porogen particles dosage and size. The porosity was up to 64.1%-78.0%. The pores were well-distributed, interconnected, and porous. The toxicity of the zein scaffold was graded as 0-1. Furthermore, PDLCs displayed full stretching and vigorous growth under scanning electronic microscope (SEM). Shuanghuangbu-scaffold extract could reinforce proliferation activity of PDLCs compared to the control group, especially at 100 microg x mL(-1) (P < 0.01).

CONCLUSIONA zein scaffold with high porosity, open pore wall structure, and good biocompatibility is conducive to the growth of PDLCs. Zein could be used as scaffold to repair periodontal tissue defects. Also, Shuanghuangbu-scaffold extract can enhance the proliferation activity of PDLCs. Altogether, these findings provide the basis for in vivo testing on animals.

Biocompatible Materials ; chemistry ; toxicity ; Cell Adhesion ; drug effects ; Cell Culture Techniques ; Cell Proliferation ; drug effects ; Cell Shape ; drug effects ; Cell Survival ; drug effects ; Cells, Cultured ; Chemical Phenomena ; Drugs, Chinese Herbal ; chemistry ; toxicity ; Humans ; Materials Testing ; Microscopy, Electron, Scanning ; Particle Size ; Periodontal Ligament ; cytology ; drug effects ; Plant Extracts ; chemistry ; pharmacology ; Polypodiaceae ; chemistry ; Porosity ; Scutellaria baicalensis ; chemistry ; Sodium Chloride ; chemistry ; Time Factors ; Tissue Engineering ; instrumentation ; methods ; Tissue Scaffolds ; chemistry ; Zein ; chemistry ; toxicity

The favorable biocompatibility of dental biomaterial is very important, which guarantees the safety and effectiveness of its clinical application. The cytotoxicity test, as one of the biological evaluation screening tests, is known to be an important and frequently used method to evaluate biocompatibility of biomaterials. This text is devoted to an overview of the cytotoxicity test for dental materials.
Biocompatible Materials ; toxicity ; Biological Assay ; methods ; trends ; Dental Materials ; toxicity ; Humans ; Materials Testing ; methods

In this paper, an immunosuppression model of immunotoxicity built through applying immunosuppressive agent-cyclophosphamide. Subsequently the changes of some assessment indexes including total amount of lymphocytes and concentration of cytokine TNF-alpha in peripheral blood were observed and were used to evaluate immunotoxicity induced by Medical Heat Vulcanizing Silicone Rubber. The final results showed no immunosuppressive effect caused by this material. The study provide effective and sensitive detection technique for evaluation of medical devices and biomaterials' immunotoxicity.
Animals ; Biocompatible Materials ; toxicity ; Elastomers ; toxicity ; Female ; Immunosuppressive Agents ; Lymphocytes ; immunology ; Male ; Materials Testing ; Mice ; Rubber ; toxicity ; Silicones ; toxicity ; Tumor Necrosis Factor-alpha ; blood