Genotoxicity evaluation of medical devices: A regulatory perspective.

This review critically evaluates our current regulatory understanding of genotoxicity testing and risk assessment of medical devices. Genotoxicity risk assessment of these devices begins with the evaluation of materials of construction, manufacturing additives and all residual materials for potential to induce DNA damage. This is followed by extractable and/or leachable (E&L) studies to understand the worst case and/or clinical exposures, coupled with risk assessment of extractables or leachables. The TTC (Threshold of Toxicological Concern) approach is used to define acceptable levels of genotoxic chemicals, when identified. Where appropriate, in silico predictions may be used to evaluate the genotoxic potentials of identifiable chemicals with limited toxicological data and above the levels defined by TTC. Devices that could not be supported by E&L studies are evaluated by in vitro genotoxicity studies conducted in accordance with ISO10993-3 and 33. Certain endpoints such as 'site of contact genotoxicity' that are specific for certain classes of medical devices are currently not addressed in the current standards. The review also illustrates the potential uses of recent advances to achieve the goal of robust genotoxicity assessment of medical devices which are being increasingly used for health benefits. The review also highlights the gaps for genotoxicity risk assessment of medical devices and suggests possible approaches to address them taking into consideration the recent advances in genotoxicity testing including their potential uses in biocompatibility assessment.

Antihyperlipidemic effect of iridoid glycoside deacetylasperulosidic acid isolated from the seeds of Spermacoce hispida L. - A traditional antiobesity herb.

ETHNOBOTANICAL RELEVANCE: The interest on herbal health supplements for obesity is increasing globally. Our previous ethnobotanical survey in Tiruvallur district, Tamil Nadu, India indicated the use of Spermacoce hispida L. seeds for the treatment of obesity. AIM OF THE STUDY: This study was aimed to validate the traditional claim and to identify the antihyperlipidemic principle in the seeds of Spermacoce hispida using bioassay guided fractionation method. METHODS: Bioassay monitored fractionation of the aqueous extract from Spermacoce hispida seeds was carried out using triton WR 1339 induced hyperlipidemic animals. It yielded deacetylasperulosidic acid (DAA) as the active ingredient. Pharmacokinetic properties of DAA were predicted using DataWarrior and SwissADME tools. In vitro antiobesity and antihyperlipidemic effects of DAA were evaluated in 3T3L1 preadipocytes and HepG2 cells, respectively. The chronic antihyperlipidemic efficacy of DAA was evaluated in high fat diet fed rats. RESULTS: DAA did not show any mutagenic and tumorigenic properties. It bound with PPARα with comparable ligand efficiency as fenofibrate. The treatment with DAA significantly lowered the proliferation of matured adipocytes, but not preadipocytes. The treatment of steatotic HepG2 cells with DAA significantly decreased the LDH leakage by 43.03% (P < 0.05) at 50 µM concentration. In triton WR 1339 induced hyperlipidemic animals, the treatment with 50 mg/kg dose significantly lowered the TC, TG and LDL-c levels by 40.27, 46.00 and 63.65% respectively. In HFD fed animals, the treatment at 10 mg/kg decreased BMI and AC/TC ratio without altering SRBG. It also improved serum lipid, transaminases and phosphatases levels of HFD fed animals. The treatment lowered adipocyte hypertrophy and steatosis of hepatocytes. CONCLUSION: This preliminary report supported the traditional use of Spermacoce hispida for the treatment of obesity. Further detailed investigations on the long term safety, efficacy and molecular mode of action of Spermacoce hispida and DAA will throw more light on their usefulness for the management of obesity.

Biocompatibility studies on cerium oxide nanoparticles - combined study for local effects, systemic toxicity and genotoxicity via implantation route.

An implantation study of cerium oxide nanoparticles (CeO2-NP) combined with 28-day systemic toxicity and genotoxicity studies aligned to current regulatory standards was conducted. The results suggested that local tissue reactions caused by CeO2-NP was minimal (implantation irritation index of less than 3) and was better tolerated than most other implant materials tested in our laboratory. Furthermore, CeO2-NP showed virtually no systemic toxicity or in vivo micronucleus induction in bone marrow via implantation route. Chemical analysis showed that CeO2-NP migrated from the implant sites (250 mg per site) in low levels and was deposited predominantly in liver (191.8 ± 35.1 ng g-1 of tissue; P < 0.01), lungs (263.4 ± 30.9 ng g-1 of tissue; P < 0.001), spleen (211.2 ± 6.5 ng g-1 of tissue; P < 0.001) and kidneys (272.8 ± 20.4 ng g-1 of tissue; P < 0.001). These observations provide a base line biocompatibility and toxicity data on CeO2-NP. The current findings will also be useful in defining standards for nanoparticle containing biomaterials and devices.

Pharmacological and toxicological evaluation of Sulcona(®), a traditional Siddha medicine used in the treatment of burns.

Sulcona, a Siddha proprietary medicine used for the treatment of burns, has been in practice for more than 50 years. This medicine has been successfully used on several burned patients with an excellent recovery and safety record. In this manuscript, we investigate some of its pharmacological and safety profiles. Treatment of cells with Sulcona induced a statistically significant increase in population doubling compared to concurrent controls in proliferating human lymphocytes as well as in Balb/c 3T3 cells, suggesting that it stimulates cell proliferation. Sulcona exhibited some antibacterial activity against Pseudomonas aeruginosa, Salmonella typhi and Staphylococcus aureus. Carrageenan-induced rat paw edema testing suggested that Sulcona has some anti-inflammatory properties. Patch testing showed that Sulcona has mild anesthetic effects. The above properties suggest Sulcona's pharmacological properties aidin treatment of burns. Sulcona did not show any skin irritation or sensitization or mutagenic potential suggesting that it is safe for use. Further work is necessary to elucidate its exact mechanisms of action.