Fuente: Journal of applied polymer Lugar: RESEARCH ARTICLE This work demonstrates a sustainable and simplified process for the production of medical-grade chitosan from the feathers of the squid Loligo plei, employing mild chemical treatments to preserve the integrity of the polymer while achieving high purity and performance. The resulting chitosan meets pharmacopoeial standards, exhibiting a high degree of deacetylation, low endotoxin levels, and excellent physicochemical properties, enabling its application in advanced biomedical areas such as drug delivery, wound healing, and tissue engineering.

ABSTRACT
This study presents an efficient, scalable method for producing medical-grade chitosan from Loligo plei squid pens under milder, more sustainable processing conditions. High yields were achieved while preserving the integrity of the polymer chain by using gentle acid demineralization, moderate alkali concentrations, and fewer processing steps than in conventional deacetylation protocols. The resulting chitosan met stringent pharmacopeial standards, exhibiting endotoxin levels below 0.25 EU/mg, residual ash content under 1%, and undetectable levels of heavy metals. Notably, the CHDM45 sample exhibited both high deacetylation (> 85%) and high viscosity (≥ 220 mPa s), making it suitable for advanced biomedical applications, including drug delivery systems, skin wound dressings, and bone engineering scaffolds. Furthermore, high-quality chitosan was obtained without demineralization by leveraging the inherently low mineral content and purity of the L. plei squid pen. Structural, thermal, and elemental analyses confirmed the effectiveness of the milder process in maintaining desirable material properties. This approach maximizes the value of an underutilized fishery by-product while minimizing environmental impact, aligning with principles of sustainable resource use and circular bioeconomy. As a result, L. plei emerges as a promising, sustainable source of biomedical-grade chitosan, supporting innovation in biopolymer-based materials and responsible waste valorization.