abrication and characterization of a bioactive polymethylmethacrylate-based porous cement loaded with strontium/calcium apatite nanoparticle

Author(s):Show less -

Tomazela, Larissa ^[1] ; Eufrasio Cruz, Marcos Antonio ^[1] ; Nascimento, Larissa Aine ^[2] ; Fagundes, Cecilia C. ^[2] ; da Veiga, Marcia Andreia Mesquita S. ^[1] ; Zamarioli, Ariane ^[3] ; Bottini, Massimo ^{[4, 5]} ; Ciancaglini, Pietro ^[1] ; Brassesco, Maria Sol ^[2] ; Engel, Edgard E. ^[3] ; Ramos, Ana Paula ^[1]

Affiliation

^[1] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Quim, Ribeirao Preto, SP - Brazil

^[2] Univ Sao Paulo, Fac Filosofia Ciencias & Letras Ribeirao Preto, Dept Biol, Sao Paulo - Brazil

^[3] Univ Sao Paulo, Dept Ortopedia & Anestesiol, Fac Med Ribeirao Preto, Sao Paulo - Brazil

^[4] Univ Roma Tor Vergata, Dept Expt Med, Rome - Italy

^[5] Sanford Bumham Prebys Med Discovery Inst, Sanford Childrens Hlth Res Ctr, La Jolla, CA - USA

• Document type: Journal article
• Source: Journal of Biomedical Materials Research Part A; v. 110, n. 4 NOV 2021.
• Web of Science Citations: 0

Abstract

Polymethylmethacrylate (PMMA)-based cements are used for bone reparation due to their biocompatibility, suitable mechanical properties, and mouldability. However, these materials suffer from high exothermic polymerization and poor bioactivity, which can cause the formation of fibrous tissue around the implant and aseptic loosening. Herein, we tackled these problems by adding Sr2+-substituted hydroxyapatite nanoparticles (NPs) and a porogenic compound to the formulations, thus creating a microenvironment suitable for the proliferation of osteoblasts. The NPs resembled the structure of the bone's apatite and enabled the controlled release of Sr2+. Trends in the X-ray patterns and infrared spectra confirmed that Sr2+ replaced Ca2+ in the whole composition range of the NPs. The inclusion of an effervescent additive reduced the polymerization temperature and lead to the formation of highly porous cement exhibiting mechanical properties comparable to the trabecular bone. The formation of an opened and interconnected matrix allowed osteoblasts to penetrate the cement structure. Most importantly, the gas formation confined the NPs at the surface of the pores, guaranteeing the controlled delivery of Sr2+ within a concentration sufficient to maintain osteoblast viability. Additionally, the cement was able to form apatite when immersed into simulated body fluids, further increasing its bioactivity. Therefore, we offer a formulation of PMMA cement with improved in vitro performance supported by enhanced bioactivity, increased osteoblast viability and deposition of mineralized matrix assigned to the loading with Sr2+-substituted hydroxyapatite NPs and the creation of an interconnected porous structure. Altogether, our results hold promise for enhanced bone reparation guided by PMMA cements. (AU)

• FAPESP's process: 19/25054-2 - Strontium-containing nanoparticles and their versatility for biomaterials fabrication: implications and applications in biomineralization
• Grantee: Ana Paula Ramos
• Support type: Regular Research Grants
• FAPESP's process: 17/26742-4 - DEVELOPMENT, CHARACTERIZATION AND BIOLOGICAL EVALUATION OF POROUS POLYMETHYLMETACRYLATE CEMENT COMBINED TO DIFFERENT STRONCIUM FORMULATIONS
• Grantee: Edgard Eduard Engel
• Support type: Regular Research Grants