Effect of acrylamide on cerebellar astrocyte proliferation in vitro

Performance and biocompatibility of extremely tough alginate/polyacrylamide hydrogels

Although hydrogels now see widespread use in a host of applications, low fracture toughness and brittleness have limited their more broad use. As a recently described interpenetrating network (IPN) of alginate and polyacrylamide demonstrated a fracture toughness of ≈ 9000 J/m(2), we sought to explore the biocompatibility and maintenance of mechanical properties of these hydrogels in cell culture and in vivo conditions. These hydrogels can sustain a compressive strain of over 90% with minimal loss of Young's Modulus as well as minimal swelling for up to 50 days of soaking in culture conditions. Mouse mesenchymal stem cells exposed to the IPN gel-conditioned media maintain high viability, and although cells exposed to conditioned media demonstrate slight reductions in proliferation and metabolic activity (WST assay), these effects are abrogated in a dose-dependent manner. Implantation of these IPN hydrogels into subcutaneous tissue of rats for 8 weeks led to mild fibrotic encapsulation and minimal inflammatory response. These results suggest the further exploration of extremely tough alginate/PAAM IPN hydrogels as biomaterials.

In vitro neurotoxicity study with dorsal root ganglia for acrylamide and its derivatives

Acrylamide and 6 derivatives inhibited neurite growth from rat dorsal root ganglion in culture. The half-maximum inhibition concentration (I50) varied among test compounds, ranging from 0.8 mM for acrylamide and N-hydroxymethylacrylamide to 30 mM for methacrylamide. The value correlated well with the acute oral LD50 for rats, the linear regression equation being I50 = 2.74LD50-6.52 (r = 0.897, P less than 0.05), but did not correlate with in vivo neurotoxicity for mice. Log (1/I50) was a linear function of the rate constant with glutathione (K), i.e. log (1/I50) = 0.828logK + 0.056 (r = 0.938, P less than 0.05).

Cytotoxic effects of acrylamide and its related compounds assessed by protein content, LDH activity and cumulative glucose consumption of neuron-rich cultures in a chemically defined medium

Cytotoxicity of acrylamide on neuronal cells cultured in a chemically defined medium was studied with morphological alteration, protein content, LDH activity and cumulative glucose consumption as toxicity indicators. The cumulative glucose consumption was significantly reduced by exposure to acrylamide before the other indicators were affected, suggesting that it would be the most sensitive indicator in the present study and that inhibition of glucose utilization might be one of the mechanisms of acrylamide neurotoxicity. The cumulative glucose consumption was applied for assessing cytotoxicity of acrylamide and its related compounds in neuronal cultures. The ED50 values were 0.8, 5.8, 15.0 mM for acrylamide, N-isopropylacrylamide, and methacrylamide, respectively, which are neurotoxic in in vivo studies. N,N'-methylene-bis-acrylamide, which is not reported to be neurotoxic, however, showed the lowest ED50 value, 0.2 mM, indicating that it was most potently toxic to neuronal cells. The results suggest the necessity of a cautious approach to neurotoxicity assessment from culture studies.

The influence of neuronal cells on the development of glutamine synthetase in astrocytes in vitro

The influence of neurons on the development of astroglial cells was examined in vitro using glutamine synthetase (GS) activity as an index of metabolic maturation. The GS activity in forebrain astrocytes was significantly increased (about 70%) when they were co-cultured with forebrain neuronal cells. A similar effect was also observed when astrocytes from the immature septum, hippocampus or cerebellum were co-cultured with neurons derived from the septal-diagonal band region. The magnitude of the effect was not uniform; the cerebellar astrocytes, with relatively low GS activity, showed a greater (about 290%) quantitative response to the subcortical nerve cells than did the septal (about 115%) or the hippocampal (about 120%) astroglial cells. The addition of conditioned medium derived from neuronal cultures or plating the cells on a substratum of heat-killed nerve cells, elevated the GS activity of astroglial cells by 33% and 39%, respectively. Our results indicate that a trophic factor secreted by neurons and direct contact with the nerve cell matrix, are both involved in the regulation of the differentiation of astrocytes.