Publications 2022 - Laboratory of Nanostructures IWC PAN

 

Microstructure and Mechanical Properties of Inverse Nanocomposite Made from Polylactide and Hydroxyapatite Nanoparticles

Elżbieta Pietrzykowska, Barbara Romelczyk-Baishya, Agnieszka Chodara, Iwona Koltsov, Hilary Smogór, Jan Mizeracki, Zbigniew Pakieła, Witold Łojkowski.

Materials 2022, 15, 184. doi.org/10.3390/ma15010184 (PDF).

 

Abstract:

Polymer nanocomposites have been extensively researched for variety of applications, including medical osteoregenerative implants. However, no satisfactory solutions has yet been found for regeneration of big, and so-called critical, bone losses. The requirement is to create a resorbable material which is characterized by optimum porosity, sufficient strength, and elastic moduls matching that of the bone, thus stimulating tissue regrowth. Inverse nanocomposites, where the ceramic content is larger than the polymer content, are a recent development. Due to their higher ceramic content, they may offer the required properties for bone implants, currently not met by polymer nanocomposites with a small number of nanoparticles. This paper presents inverse nanocomposites composed of bioresorbable nano crystalline hydroxyapatite (HAP NPs) and polylactide (PLLA), produced by cryomilling and a warm isostatic pressing method. The following composition were studied: 25%, 50%, 75% of HAP NPs by volume. The mechanical properties and structure of these copmpsites were examined. It was discovered that 50% volume content was optimal as faras compressive strength and porosity are concerned. The inverse nanocomposite with 50% nanoceramics volume displayed a compressive strength of 99±4MPa, a contact angle of 50ο, and 255 porosity, which make this material a candidate for further studies as a bioresorbable bone implant.

Keywords: inverse composites; biomaterials; mechanical properties