Molecular dynamics simulation of the dissolution process of a cellulose triacetate-II nano-sized crystal in DMSO

Pullulan in pharmaceutical and cosmeceutical formulations: A review

Pullulan, an α-glucan polysaccharide, is colorless, odorless, non-toxic, non-carcinogenic, highly biocompatible, edible and biodegradable in nature. The long chains of glucopyranose rings in pullulan structure are linked together by α-(1 → 4) and α-(1 → 6) glycosidic linkages. The occurrence of both glycosidic linkages in the pullulan structure contributes to its distinctive properties. The unique structure of pullulan makes it a potent candidate for both pharmaceutical and cosmeceutical applications. In pharmaceuticals, it can be used as a drug carrier and in various dosage formulations. It has been widely used in drug targeting, implants, ocular dosage forms, topical formulations, oral dosage forms, and oral liquid formulations, etc. Pullulan can be used as a potential carrier of active ingredients and their site-specific delivery to skin layers for cosmeceutical applications. It has been extensively used in cosmeceutical formulations like creams, shampoo, lotions, sunscreen, facial packs, etc. The current review highlights applications of pullulan in pharmaceutical and cosmeceutical applications.

Computational study on the interactions and orientation of monoclonal human immunoglobulin G on a polystyrene surface

Having a theoretical understanding of the orientation of immunoglobulin on an immobilized solid surface is important in biomedical pathogen-detecting systems and cellular analysis. Despite the stable adsorption of immunoglobulin on a polystyrene (PS) surface that has been applied in many kinds of immunoassays, there are many uncertainties in antibody-based clinical and biological experimental methods. To understand the binding mechanism and physicochemical interactions between immunoglobulin and the PS surface at the atomic level, we investigated the binding behavior and interactions of the monoclonal immunoglobulin G (IgG) on the PS surface using the computational method. In our docking simulation with the different arrangement of translational and rotational orientation of IgG onto the PS surface, three typical orientation patterns of the immunoglobulin G on the PS surface were found. We precisely analyzed these orientation patterns and clarified how the immunoglobulin G interacts with the PS surface at atomic scale in the beginning of the adsorption process. Major driving forces for the adsorption of IgG onto the PS surface come from serine (Ser), aspartic acid (Asp), and glutamic acid (Glu) residues.

Correlations between steric/thermochemical parameters and O-/N-acylation reactions of cellulose

N(α)-t-Butyloxycarbonyl (Boc)-amino acids (Xaa = Gly, Ala, or β-Ala) were reacted with the cellulose hydroxyl groups (O-acylation) using N,N'-carbonyl diimidazole. The degrees of substitution toward the total hydroxyl groups (DS%(/OH)s) were 38% for O-(Boc-Gly)-Cellulose, 29% for O-(Boc-Ala)-Cellulose and 53% for O-(Boc-β-Ala)-Cellulose. The one-by-one N-acylation between the O-(Xaa)-Celluloses and Boc-Ala-Gly using a water-soluble carbodiimide yielded the conjugates N-(Boc-Ala-Gly)-Xaa-Celluloses with DS%(/NH2) values of 25% (Xaa = Gly), 35% (Ala), and 48% (β-Ala), respectively. The results were well correlated with ΔG and ΔEstrain profiles, which were predicted by semi-empirical thermochemical parameter calculation coupled with conformer search (R(2)>0.90). N-acylation of the O-(β-Ala)-Cellulose using various length of oligo-peptides, Boc-(Ala-Gly)n and Boc-(Gly-Ala)n (where, n = 0.5, 1.0, 1.5, 2.0, 3.0), suggested that the DS%(/NH2) was dependent on the structural features of the symmetric anhydrides as the N-acylating agents, including conformer populations and their transition energy.