We studied the influence of 5 kDa poly(acrylic acid) (PAA) on the phase state, thermal properties, and lateral diffusion in bilayered systems of dimyristoylphosphatidylcholine (DMPC) using (31)P NMR spectroscopy, differential scanning calorimetry (DSC), (1)H NMR with a pulsed field gradient, and (1)H nuclear Overhauser enhancement spectroscopy (NOESY). The presence of PAA does not change the lamellar structure of the system. (1)H MAS NOESY cross-peaks observed for the interaction between lipid headgroups and polyion protons demonstrated only surface PAA-biomembrane interaction. Small concentrations of PAA (up to ∼4 mol %) lead to the appearance of a new lateral phase with a higher main transition temperature, a lower cooperativity, and a lower enthalpy of transition. Higher concentrations lead to the disappearance of measurable thermal effects. The lateral diffusion coefficient of DMPC and the apparent activation energy of diffusion gradually decreased at PAA concentrations up to around 4 mol %. The observed effects were explained by the formation of at least two types of PAA-DMPC lateral complexes as has been described earlier (Fujiwara, M.; Grubbs, R. H.; Baldeschwieler, J. D. J. Colloid Interface Sci., 1997, 185, 210). The first one is characterized by a stoichiometry of around 28 lipids per polymer, which corresponds to the adsorption of the entire PAA molecule onto the membrane. Lipid molecules of the complex are exchanged with the "pure" lipid bilayer, with the lifetime of the complex being less than 0.1 s. The second type of DMPC-PAA complex is characterized by a stoichiometry of 6 to 7 lipids per polymer and contains PAA molecules that are only partially adsorbed onto the membrane. A decrease in the DMPC diffusion coefficient and activation energy for diffusion in the presence of PAA was explained by the formation of a new cooperative unit for diffusion, which contains the PAA molecule and several molecules of lipids.

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Aim: Evaluation of the effect of glucosamine-chondroitin combination, tramadol, and sodium hyaluronic acid in temporomandibular joint (TMJ) disorders and its impact on the expression of various cytokines such as IL-6, IL-1ß, TNF-α, and PGE2. Materials and methods: The present study was conducted on 60 patients (males-30, females-30) suffering from internal derangement such as disc displacement with reduction of TMJ. The patients were divided into three groups of 20 each. Group I received a combination of 1.5g of glucosamine and 1.2 g of chondroitin sulfate per day and group II received 50 mg tramadol HCL peroral. Group III received sodium hyaluronate 10 mg/mL, 2 mL injection syringe on each joint. Pain (VAS) scale and maximum mouth opening (MMO) was measured. The level of IL-6, IL-1ß, TNF-α, and PGE2 levels were measured using Enzyme-linked immuno sorbent assay (ELISA). Results: There was an improvement in maximum mouth opening in all three groups (p < 0.05). There was a reduction in pain in all groups. IL-1 ß, TNF-α, and PGE2 leve ls showed reduction while IL-6 showed an increase in value in group II and III. Conclusion: The efficacy of glucosamine chondroitin sulfate , tramadol and hyaluronic acid in TMJ disorders has been found to be effective. Clinical significance: IL-6, IL-1ß, TNF-α, and PGE2 levels indicate the risk of TMJ disorders. Thus earlier assessment of their levels helps in diagnosis, and better management may be done.