Polyurethane derived from castor oil monoacylglyceride (Ricinus communis) for bone defects reconstruction: characterization and in vivo testing

João Pedro Pereira De Morais,Ana Cristina Vasconcelos Fialho,Marcia Dos Santos Rizzo,Felipe José Costa Viana,Fernando Da Silva Reis,Daniel Cabral Leão Ferreira,Isnayra Kerolaynne Carneiro Pacheco,José Milton Elias De Matos,Antonio Luiz Martins Maia Filho

doi:10.1007/s10856-021-06511-z

João Pedro Pereira De Morais, Ana Cristina Vasconcelos Fialho + Show 7 more

Open Access

https://doi.org/10.1007/s10856-021-06511-z

Copy DOI

Abstract

Biomaterials used in tissue regeneration processes represent a promising option for the versatility of its physical and chemical characteristics, allowing for assisting or speeding up the repair process stages. This research has characterized a polyurethane produced from castor oil monoacylglyceride (Ricinus communis L) and tested its effect on reconstructing bone defects in rat calvaria, comparing it with commercial castor oil polyurethane. The characterizations of the synthesized polyurethane have been performed by spectroscopy in the infrared region with Fourier transform (FTIR); thermogravimetric analysis (TG/DTG); X-ray diffraction (XRD) and Scanning Electron Microscopy (SEM). For the in vivo test, 24 animals have been used, divided into 3 groups: untreated group (UG); control group treated with Poliquil® castor polyurethane (PCP) and another group treated with castor polyurethane from the Federal University of Piauí - UFPI (CPU). Sixteen weeks after surgery, samples of the defects were collected for histological and histomorphometric analysis. FTIR analysis has shown the formation of monoacylglyceride and polyurethane. TG and DTG have indicated thermal stability of around 125 °C. XRD has determined the semi-crystallinity of the material. The polyurethane SEM has shown a smooth morphology with areas of recesses. Histological and histomorphometric analyzes have indicated that neither CPU nor PCP induced a significant inflammatory process, and CPU has shown, statistically, better performance in bone formation. The data obtained shows that CPU can be used in the future for bone reconstruction in the medical field.

Highlights

Bone defects commonly caused by trauma, congenital deformities, or inflammatory diseases still represent a challenge for orthopedics, oral and maxillofacial surgery, with bone tissue engineering having the aim of helping in their reconstruction [1, 2]
Twenty-four adult male rats (Rattus norvegicus, Wistar) have been used, randomly divided into 3 groups (n = 8), according to the material used or not for calvaria reconstruction: untreated group (UG), control group treated with Poliquil® castor polyurethane (PCP) and castor polyurethane University of Piauí (UFPI) (CPU)
The FTIR of MAG, obtained from castor oil (CO) and polyurethane, is observed in Fig. 1a, b a band at 3300 cm−1 is noted, which corresponds to the stretching vibration of OH groups present in glycerol and MAG

Summary

Introduction

Bone defects commonly caused by trauma, congenital deformities, or inflammatory diseases still represent a challenge for orthopedics, oral and maxillofacial surgery, with bone tissue engineering having the aim of helping in their reconstruction [1, 2]. For this purpose, it is necessary to use biomaterials that accelerate or assist the standard and complete repair of the defect [3]. Castor oil-based polyurethanes have been widely explored for biomedical devices and tissue engineering applications, thanks to their qualities such as good biocompatibility, biodegradability, naturally occurring hydroxyl groups, and easy chemical modification. The synthesis of polyurethane results from the reaction between a compound with two or more isocyanates and polyfunctional alcohol (hydroxylated low molecular weight polymer or polyol) [7,8,9]

Objectives

Methods

Results

Conclusion