Influence of chitosan-tripolyphosphate nanoparticles on thermosensitive polymeric hydrogels: structural organization, drug release mechanisms and cytotoxicity

Abstract

Chitosan-tripolyphosphate (CS-TPP) nanoparticles containing naproxen (NPX) were dispersed in poloxamer (PL) as unique (PL407) or binary (PL407-PL403) systems. Nanoparticles presented diameter of ∼250 nm and zeta potential of ∼35 mV with drug loading and encapsulation efficiency of 98.4 ± 0.3% and 36.9 ± 0.12%, respectively. NPX-CS-TPP shifted the sol-gel transition and micellization temperatures. PL407-PL403 systems presented G′ > G″ compared to PL407. SAXS patterns revealed transitions from lamellar to hexagonal phase organizations with low drug release rates, in the presence of CS-TPP nanoparticles. NPX-CS-TPP-PL407 induced lower cytotoxicity compared to PL407-PL403 in fibroblasts and osteoblasts, making them promising systems for intra-articular delivery.

Graphical Abstract

KEYWORDS:

• Arthritis
• chitosan nanoparticles
• hydrogels
• naproxen
• poloxamer

Additional information

Funding

This research work was supported by Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES), Fundação de Amparo à Pesquisa do Estado de São Paulo [FAPESP 2014/26200-9, 2014/14457-5, 2014/12653-1] and Conselho Nacional de Desenvolvimento Científico e Tecnológico [CNPq 309207/2016-9, 402838/2016-5]. Authors are also grateful to the Brazilian Synchrotron Light Laboratory for SAXS facilities (SAXS 1 beamline) and UFABC Multiuser Central Facilities (CEM-UFABC).