Poly cytotoxicity test

Chitosan nanofibers have been eiectrospun as blends with very low concentrations of PEG to enhance cell attachment and promote the liver function of hepatocy tes cultured in bioreactors (Chu et al. 2009 Bhattarai et al. 2005). Eiectrospun nanofibers of a chitosan-hydroxybenzotriazole (CS-HOBt)/poly vinyl alcohol (PVA) blend were prepared without organic solvent or organic acids (Charemsriwilaiwat et al. 2010). The morphologies of the fibers and their diameters were strongly influenced by the weight ratio in this blend. Cytotoxicity tests showed that CS-HOBt/PVA nanofiber membranes were nontoxic to fibroblast cells. 

Attawia, M.A., Uhrich, K.E., Botchwey, E., Fan, M., Langer, R., Laurencin, C.T., 1995. Cytotoxicity testing of poly (anhydride-co-imides) for orthopedic applications. Journal of Biomedical Materials Research 29, 1233—1240. 

Although the initially reported tissue compatibility tests for subcutaneous implants of poly(BPA-iminocarbonate) were encouraging (41,42), it is doubtful whether this polymer will pass more stringent biocompatibility tests. In correspondence with the properties of most synthetic phenols, BPA is a known irritant and most recent results indicate that BPA is cytotoxic toward chick embryo fibroblasts in vitro (43). Thus, initial results indicate that poly(BPA-iminocarbonate) is a polymer with highly promising material properties, whose ultimate applicability as a biomaterial is questionable due to the possible toxicity of its monomeric building blocks. 

Non-natural peptides involved in the stabilization of the MFIC class I molecules can be considered as the starting point for the discovery of new immune modulators such as antitumor vaccines and T-cell receptor agonists or antagonists [44-48]. In this context, poly-N-acylated amines (PAAs) as a new class of synthetic oligomers were developed and tested as ligands for the murine class I molecule H-2Kb [49]. Based on the natural cytotoxic T-cell epitope SIINFEKL, non-peptidic structural elements were introduced in the C-ter-minal part of the ligand including the anchor positions 5 (Phe) and 8 (Leu) (Fig. 7.7). 

Not much is known about the toxicity of cyclophanes. p-xylylenes, cy-clophanes and halogen substituted p-xylylenes show minor toxic effects. However, the polymer class is extensively used in medical applications. The cytotoxicity of poly(2(3)-(4-phenylbutyl)-l,4-phenyleneethylene)has been tested by in vitro experiments and showed a mild toxicity. ... 

Poly(lysine-C( -phthalamide) has been characterized with side chains of poly(ethylene glycol) (PEG) or Jeffamine M-1000 , a hydrophilic PEG analogue [33-35]. These polymers show minimal cytotoxicity when tested against HeLa and Chinese hamster ovarian cells, where viability is at least 60% at polymer concentrations of 2 mg/ml [34]. Poly(lysine-C( -phthalamide) is generally nonhemolytic at physiological pH, but the incorporation of... 

It has clearly been shown that inhibition of poly(ADP-ribose) synthetase was responsible for the cytotoxicity exhibited by five of the six benzamides tested. 3-Nitrobenz-amide was markedly more cytotoxic than would be expected on the basis of its K,. Nitro-compounds have been shown to be cytotoxic and genotoxic. This is thought to arise by reduction to reactive intermediates which can then modify DNA [3]. When uridine incorporation was correlated with the Hammet constant, 3-nitrobenzamide fitted very well. The shorter exposure time in this assay minimises any metabolite effects. 

In some recent studies it has been reported that 3-aminobenzamide (SAB), an inhibitor of poly(ADP-ribose) polymerase [7, 10] also inhibits the pathway for de novo synthesis of DNA precursors. Specifically, SAB inhibits the metabolism of glucose and methionine into precursors of DNA in WI-L2 lymphoid cells [6], C3H mouse fibroblasts [1], and Chinese hamster ovary (CHO) cells [4]. It has been suggested that some of the reported effects of SAB, such as its effect on cell-cycle progression [8], may be due to a disturbance in nucleotide precursor pathways rather than an inhibition of poly(ADP-ribose) synthesis [1—4, 6]. To test this hypothesis, we have examined the effects of SAB on SCE induction, cytotoxicity, and cell-cycle progression in three different human lymphoblastoid cell lines two deficient in salvage nucleotide synthesis pathways and one competent in both salvage and de novo nucleotide synthesis. We hypothesized that if SAB inhibits de novo nucleotide synthesis pathways, then cells deficient in salvage nucleotide synthesis pathways should be more sensitive to the various effects of SAB, especially its cytotoxic and cell-cycle effects. 

PLA composites containing flax fibres rich in poly(hydro3ybulyrate) (PHB) as reinforcement were prepared by compression moulding and further analyzed. Biochemical analysis of fibres revealed the presence of several antioxidant compounds, including cannabidiol and lutein. The prepared composites seem to have bacteriostatic, platelet anti-aggregated and non-cytotoxic effect. No tests on compound migration were reported. 

The medical grade silicone rubber Sylgard 184 consists of a crosslinked poly-dimethylsiloxane. In vitro and in vivo testing has proven the non-cytotoxicity in direct and indirect contact. There is no ocular toxicity and no acute foreign body reaction in contact with soft tissues. 

As an example of a selectively acting drug carrier, we would like to mention also the PDEPT (polymer-directed enzyme prodrug therapy) approach based on combination of HPMA copolymer prodrug with the poly(HPMA)-enzyme conjugate selectively generating the cytotoxic drug within tumor. As an example a combination of PKl and polymer-cathepsin B system can be cited but also other combinations were tested. HPMA-based polymers with a micellar or dendritic structure have been also intensively studied they are described in separate chapters. 

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