Hydroxyapatite Obtained via the Wet Precipitation Method and PVP/PVA Matrix as Components of Polymer-Ceramic Composites for Biomedical Applications.

Magdalena Głąb,Bożena Tyliszczak,Janusz Walter,Aleksandra Kordyka,Rafał Bogucki,Marcin Godzierz,Anna Drabczyk,Agnieszka Sobczak-Kupiec,Sonia Kudłacik-Kramarczyk

doi:10.3390/molecules26144268

Abstract

The aspect of drug delivery is significant in many biomedical subareas including tissue engineering. Many studies are being performed to develop composites with application potential for bone tissue regeneration which at the same provide adequate conditions for osteointegration and deliver the active substance conducive to the healing process. Hydroxyapatite shows a great potential in this field due to its osteoinductive and osteoconductive properties. In the paper, hydroxyapatite synthesis via the wet precipitation method and its further use as a ceramic phase of polymer–ceramic composites based on PVP/PVA have been presented. Firstly, the sedimentation rate of hydroxyapatite in PVP solutions has been determined, which allowed us to select a 15% PVP solution (sedimentation rate was 0.0292 mm/min) as adequate for preparation of homogenous reaction mixture treated subsequently with UV radiation. Both FT-IR spectroscopy and EDS analysis allowed us to confirm the presence of both polymer and ceramic phase in composites. Materials containing hydroxyapatite showed corrugated and well-developed surface. Composites exhibited swelling properties (hydroxyapatite reduced this property by 25%) in simulated physiological fluids, which make them useful in drug delivery (swelling proceeds parallel to the drug release). The short synthesis time, possibility of preparation of composites with desired shapes and sizes and determined physicochemical properties make the composites very promising for biomedical purposes.

Highlights

Bone surgery and tissue engineering are currently some of the most rapidly developing fields of medicine
Ammonium phosphate monobasic (NH4H2PO4, ACS reagent, ≥98%), calcium nitrate tetrahydrate (Ca(NO3)2·4H2O, ACS reagent, 99%) and ammonia water (NH4OH, 25%) used for the synthesis of hydroxyapatite as well as diacrylate poly(ethylene glycol) (crosslinking agent, average molecular weight Mn = 700 g/mol (PEGDA 700) and Mn = 575 g/mol (PEGDA 575)); 2-hydroxy-2-methylpropiophenone, poly(vinyl alcohol) (PVA, Mw = 13,000–23,000 g/mol; 87–89%; hydrolyzed, crystalline powder) and polyvinylpyrrolidone (PVP, average molecular weight 10,000 g/mol, powder) used for the synthesis of composites were bought from Sigma Aldrich (Saint Louis, MO, USA)
The performed X-ray diffraction (XRD) analysis indicated that two-phase material consisting of hydroxyapatite and tricalcium phosphate was prepared as a result of wet precipitation method

Summary

Introduction

Bone surgery and tissue engineering are currently some of the most rapidly developing fields of medicine. Other factors affecting the loss of bone tissue density or mass are traffic accidents, old age and sport-related injuries such as fractures [3]. The most popular approach for bone defect repair is surgical treatment via autologous or artificial bone grafting. These methods are related to the occurrence of such complications as, e.g., strong pain in the site of the surgery or transmission of various pathogens, which may contribute to additional health problems such as sepsis. Alternative methods are being sought and one of them seems to be an application of synthetic materials with might affect the osteoblasts to differentiate and form new tissue which will fill the defect [4]

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Results

Conclusion