A series of new replacement methods of skin irritation test such as EpiSkin, EpiDermSIT (updated) and SkinEthicRHE have been validated by ECVAM. Due to it, animals are protected to the full extent. These provide more methods for biological evaluation of medical devices.
Animal Testing Alternatives ; methods ; Humans ; Skin Irritancy Tests ; methods

OBJECTIVETo evaluate the skin irritation and sensitization potential of the swine acellular dermal matrix treated with hyaluronic acid (SADM-HA).

METHODS(1) Skin irritation test. Twelve New Zealand rabbits were divided into SADM-HA group, allogeneic skin group, and (human) xeno-skin group according to the random number table, with 4 rabbits in each group. Four test sites were designed on the back of each rabbit. Two test sites of each rabbit in the three groups were covered with SADM-HA, allogeneic skin, and xeno-skin, respectively. Another test site was covered with gauze containing 200 g/L sodium dodecyl sulfate solution as positive control. The last test site was covered with gauze containing normal saline as negative control. The primary irritation index and cumulative irritation index of each material were calculated. (2) Skin closed-patch test. Sixty guinea pigs were used. Fifty-four guinea pigs were divided into SADM-HA group, allogeneic skin group, and (human) xeno-skin group according to the random number table, with 18 guinea pigs in each group. Twelve guinea pigs in each of the three groups were correspondingly induced and stimulated by SADM-HA, allogeneic skin, and xeno-skin, with 6 guinea pigs in each group treated with ethanol-soaked gauze to serve as negative control. The remaining 6 guinea pigs were treated with gauze containing 25% α-hexylcinnamaldehyde ethanol solution as positive control. The rating scales of Magnusson and Kligman were used to grade the condition of skin after being treated with above-mentioned materials to evaluate skin sensitivity to them at post stimulation hour 24 and 48. Data were processed with the non-parametric test of independent samples.

RESULTS(1) In the skin irritation test, the primary irritation indexes of the three dressings in SADM-HA group, allogeneic skin group, and xeno-skin group were respectively -0.04, 0.13, and 0.08. The cumulative irritation indexes of the three dressings in SADM-HA group, allogeneic skin group, and xeno-skin group were respectively 0.27, 0.10, and 0.25, which were close to those of negative control within the three groups. The skin irritation of each of the three materials was negligible. (2) In the skin closed-patch test, all scores of the three dressings in SADM-HA group, allogeneic skin group, and xeno-skin group were between 0 and 1. The scores of SADM-HA group and allogeneic skin group were close to those of negative control within the two groups (with U values respectively 188.00 and 90.00, P values both above 0.05). The differences were statistically significant between each material of the three groups and positive control (with U values respectively 19.00, 59.00, 21.50, P values all below 0.01).

CONCLUSIONSThe SADM-HA is safe and reliable without skin irritation and sensitization, and it has encouraging prospect in clinical application.

Acellular Dermis ; adverse effects ; Animals ; Guinea Pigs ; Hyaluronic Acid ; adverse effects ; Rabbits ; Skin ; Skin Irritancy Tests ; Skin Transplantation ; methods ; Swine

Chitosan-carboxymethyl-chitosan complex film was prepared by freeze drying. Some tests in vivo and in animal were employed, in order to evaluate it on biology. All results indicated that the film has not only good surface compatibility but also good structural compatibility. It can be more suitable for GTR technology.
Animals ; Biocompatible Materials ; chemical synthesis ; pharmacology ; Chitin ; analogs & derivatives ; Chitosan ; Materials Testing ; Membranes, Artificial ; Rabbits ; Rats ; Skin Irritancy Tests

According to ISO 10993 standard series, the biological safety of surface modified pure titanium was studied as a percutaneous device by the test of cytotoxicity in vitro, as well as by the tests of irritation and sensitization. The result from the examination of cytotoxicity in vitro was negative, the skin irritation response was negligible, and the result of test on skin sensitization in guinea pigs was also negligible. So the surface modified pure titanium in this study can be safely used as percutaneous implanting materials.
Animals ; Biocompatible Materials ; chemistry ; Coated Materials, Biocompatible ; chemistry ; Female ; Guinea Pigs ; Implants, Experimental ; adverse effects ; Materials Testing ; Rabbits ; Random Allocation ; Skin Irritancy Tests ; methods ; Surface Properties ; Titanium ; chemistry

OBJECTIVETo evaluate the toxicity of chicken calamus keratin (CCK) conduit as a tissue-engineered scaffold material.

METHODSThe chemical composition of the leaching solution of CCK was determined by means of ultraviolet spectrometry, and the toxic effects of the solution was evaluated by skin sensitization test in rats, intracutaneous stimulation test in rabbits, acute systemic toxicity test in mice, and cytotoxicity test in L929 cells.

RESULTSThe leaching solution of CCK consisted mainly of middle-molecular-weight peptides with a small quantity of macromolecular proteins. Skin sensitization test in rats showed that application of the CCK leaching solution caused no obvious skin reddening, regional edema, or skin necrosis. Intracutaneous injection of the leaching solution in rabbits did not induce obvious skin stimulation manifested by intradermal erythema or edema. In acute systemic toxic test, administration of the leaching solution in mice caused no death, organ dysfunction, cyanosis, tremor, severe peritoneal irritation, ptosis, or dyspnoea. In vitro cytotoxicity test indicated that the cell toxicity of the CCK leaching solution was approximately at 0 level.

CONCLUSIONCCK contained in the treated chicken calamus easily undergoes hydrolysis to release mainly some peptides which do not induce obvious toxic effects, suggesting the safe potential applications of CCK conduit as a tissue-engineering biomaterial.

Animals ; Cell Line ; Cell Proliferation ; drug effects ; Chickens ; Feathers ; chemistry ; Female ; Keratins ; chemistry ; toxicity ; Male ; Mice ; Rabbits ; Rats ; Skin Irritancy Tests ; Solutions ; Tissue Engineering ; Tissue Scaffolds ; chemistry ; Toxicity Tests ; methods

OBJECTIVETo investigate biosynthetic and apoptotic mechanisms in repair of full thickness skin defect with collagen-chitosan porous scaffold transplantation, and to determinate differences between wound repair with the scaffold transplantation and scar healing without the scaffold transplantation.

METHODSThe full thickness skin defects were made on 10 Bama miniature pigs and the bilayer dermal equivalent (BDE) composed of collagen-chitosan porous scaffold and silicone membrane was transplanted on wounds. Surfaces of wounds were observed at 1, 2, and 3 weeks after the BDE transplantation, and so were done the wound repairs after epidermis had been grafted for 2 weeks on surface of the scaffold which had been transplanted on skin defect wounds for 2 weeks. At the same time, TGF-beta1 expressions, apoptosis and self collagen replacement of scaffolds in wounds were detected in situ by immunohistochemical staining, terminal deoxynucleotidyl transferase-mediated deoxyuridine triphosphate-biotin nick end labeling (TUNEL) and picrosirius red polarized light. Wounds without scaffold transplantation were studied as control.

RESULTS1) Wounds with the scaffold transplantation were different from granulation tissue. 2) The peak of TGF-beta1 expression in the scaffold wounds was from 1 to 2 weeks after BDE transplantation, and TGF-beta1 expressions decreased continuously from 3 to 4 weeks. TGF-beta1 expressions increased continuously in the control wounds from 1 to 3 weeks and decreased on 4 weeks. TGF-beta1 expressions in the scaffold wounds on 1st and 2nd week were significantly higher than those in the corresponding control wounds, whereas, TGF-beta1 expressions in the scaffold wounds on 3rd and 4th week were significantly lower than those in the corresponding control wounds. 3) Apoptosis increased continuously in the scaffold wounds from 2 to 4 weeks after BDE transplantation, and so did in the control wounds from 3 to 4 weeks. However, apoptosis signals in the scaffold wounds on 2nd, 3rd, and 4th week after BDE transplantation were significantly more than those in the corresponding control wounds, and there was no difference between apoptosis signals in the scaffold wounds on 1st week after BDE transplantation and those in the corresponding control wounds. 4) Observation by picrosirius red polarized light method: self collagen began to synthesize in the scaffold wounds on 1st week after BDE transplantation, and scaffolds had been replaced by self collagen from 2 to 3 weeks after BDE transplantation.

CONCLUSIONSCollagen-chitosan porous scaffold plays a very important role in wound healing of full thickness skin defect. The mechanisms of wound repair by dermal scaffold are different from those by granulation and scar healing. It has a good future in repairing skin defect.

Animals ; Apoptosis ; Chitosan ; metabolism ; Collagen ; biosynthesis ; metabolism ; Dermis ; Extracellular Matrix ; Female ; Skin Irritancy Tests ; Skin, Artificial ; Stents ; Swine ; Swine, Miniature ; Tissue Engineering ; Transforming Growth Factor beta1 ; metabolism ; Wound Healing

OBJECTIVETo study the changes of nitric oxide (NO) in the BALB/c hairless mice skin after trichloroethylene (TCE) irritation and the protection of ginkgo biloba extract (GbE) and vitamin E (VE).

METHODS132 BALB/c hairless mice were randomly divided into blank control group, solvent group (olive oil), TCE groups (20%TCE, 40%TCE, 80%TCE and 100%TCE), GbE groups (0.1%GbE, 1%GbE and 10%GbE) and VE groups (5%VE, 10% VE and 20% VE), with 11 animals in each group, 5 for acute irritation test and 6 for the cumulative irritation test. The skin irritation was observed, and the levels of NO in the dorsal skin of BALB/C hairless mice were detected. The kit of NO was used to detect the levels of NO in the dorsal skin of BALB/c hairless mice.

RESULTS(1) The skin presented erythema and edema after TCE irritation both in acute irritation and cumulative irritation test and the skin inflammation showed time-dose effect relationship; the mice skin was protected in GbE or VE groups. (2) In the acute stimulation test, the levels of NO in 80%TCE group (69.895 +/- 9.605 micromol/mg pro) and 100%TCE group (77.273 +/- 9.290 micromol/mg pro) were significantly different compared with blank control group and solvent control group (P < 0.05 or P < 0.01). In the protection group, the NO level were reduced, with the statistically significant differences. (3) In acute irritation test, the levels of NO in 80%TCE group (60.362 +/- 9.817 micromol/mg pro) and 100%TCE group (68.027 +/- 9.354 micromol/mg pro) were significantly different compared with blank control group and solvent control group, (P < 0.05 or P < 0.01); In the protection group, 1% GbE, 10% GbE, 10% VE and 20%VE could reduce the levels of NO, with statistically significant differences.

CONCLUSIONTCE can produce the irritation on the dorsal skin of BALB/c hairless mice and induce the significant increase of the NO levels. GbE and VE can protect the skin from TCE irritation damage.

Animals ; Female ; Ginkgo biloba ; chemistry ; Mice ; Mice, Hairless ; Mice, Inbred BALB C ; Nitric Oxide ; metabolism ; Plant Extracts ; pharmacology ; Skin ; drug effects ; metabolism ; Skin Irritancy Tests ; Trichloroethylene ; toxicity ; Vitamin E ; pharmacology

OBJECTIVE: To investigate aeroallergen spectrum of patients with allergic rhinitis in Changsha area and analyze its related factors. METHOD: Skin prick test was carried out in 463 cases with allergic rhinitis using 13 inhaled allergens, and detailed history was collected in all cases. RESULT: Three hundred and eighty-seven cases (83.6%) showed positive reaction to at least one allergen of 13 allergens. The most common allergens found in patients were Dermatophagoides farinae and Dermatophagoides pteronyssinus, followed by tropical mite, Periplaneta americana, Blattella germanica and dog hair. The rate of positive reaction to only one specie allergen were 51.9%, and most of them were positive reaction to mites (49.6%). The degree of positive reaction was significantly related to family history, asthma, age and housing environment. CONCLUSION The major allergen of allergic rhinitis is mite, and the degree of positive reaction relates to genetics, asthma, age and housing environment.
Adolescent ; Adult ; Aged ; Allergens ; analysis ; Animals ; Child ; Child, Preschool ; China ; epidemiology ; Dogs ; Female ; Humans ; Male ; Middle Aged ; Pyroglyphidae ; immunology ; Rhinitis, Allergic, Perennial ; epidemiology ; immunology ; Skin Irritancy Tests ; Young Adult

OBJECTIVETo create an externally-applied TCD plaster (Laosun Yutie plaster) for the lumbar muscle strain (LMS).

METHOD(1) The raw material such as angelica, safflower, frankincense, myrrh, clove and so on were turned into solid TCD plaster by a serial of modern treatment technology-distillation, extraction, condense, dehydration. Meanwhile, the naphtha from the distillation process and borneol were dissolved into ethanol solution and the dilution was thus made; (2) The solid TCD plaster and the dilution from the aboved-mentioned process were put together to form the TCD plaster and the corresponding safety experiments were applied to rabits' skin.

RESULTThe experimental results showed that it is neither of urgent toxicity, stimulary function, nor of allergy-inducing response.

CONCLUSIONThe laosun Yutie plaster was a newly externally-applied TCD plaster which could be used safely and handily.

Administration, Cutaneous ; Animals ; Drug Combinations ; Drugs, Chinese Herbal ; administration & dosage ; isolation & purification ; toxicity ; Exanthema ; chemically induced ; Female ; Guinea Pigs ; Hypersensitivity ; etiology ; Male ; Plants, Medicinal ; chemistry ; Rabbits ; Skin Irritancy Tests