Tuning Biodegradation and Physicochemical Features of PLA/HAp Biomaterials by Incorporating Nanofibrillated Cellulose Through a Colloidal Processing Route

Biomaterials play a fundamental role in providing a porous structure that mimics the natural structure of human bone and serves as a support while tissue regenerates. With the use of biodegradable materials, it is possible to avoid unnecessary second surgeries for implant removal. The main objective of this article has been focused on modifying the degradation rate of a biodegradable composite material based on polylactic acid (PLA) reinforced with hydroxyapatite (HAp) by incorporating nanofibrillated cellulose (NFC), capable of tuning the porosity within the matrix. To introduce NFC into the composite material, a colloidal processing approach was chosen to improve and ensure its compatibility with the polymeric matrix. The incorporation of different ratios of NFC generally decreases the mechanical properties, but by adjusting the ratio of HAp/NFC content, this parameter is normalized. The hydrophilicity of the composite is improved by HAp/NFC incorporation, and degradation tests confirm that an increase in the percentage of NFC in the matrix is directly proportional to an increase in the degradation rates of the material. These results represent a significant improvement in personalized medicine, where the design of biodegradable biomaterials with hierarchical and controlled porosity opens new paths in the development of therapies and treatments personalized for each patient.