Gamma radiation induced property modification of poly(lactic acid)/hydroxyapatite bio-nanocomposites

Abstract

Poly(lactic acid)/hydroxyapatite (PLA/HAP) nanocomposite films with various compositions, 2 − 70 parts HAP per 100 of the PLA polymer (pph), were made via the solution casting method. Transmission electron microscopy images of the PLA/HAP films exhibited spherical particles in the size range from nearly 10 nm to 100 nm dispersed within the polymeric matrix. Fourier transform infrared spectra of the nanocomposites revealed an interaction between PLA and HAP nanoparticles by carbonyl group peak shift. Incorporation of HAP nanoparticles in the PLA matrix stimulated crystal growth verified by differential scanning calorimetry. The films irradiated with γ -rays at a dose of 30 kGy also showed an increase in crystallinity. The X-ray diffraction patterns of the irradiated PLA exhibited two new peaks at around 16 • and 19 • , assigned to the α crystalline phase of PLA; these were absent in the unirradiated nanocomposites. Significant ductile behavior was observed in both irradiated and unirradiated PLA nanocomposites containing 2 and 10 pph of HAP. However, the irradiated nanocomposites had higher tensile strength.

Magnetic nanoparticles‐loaded PLA/PEG microspheres as drug carriers

“…about 100 C in order to develop a more crystalline structure with a strong characteristic diffraction peak at 16.7 . 7 In the preparation methods used in this work, PLA solution temperature remained just moderately above room temperature and so the chance of PLA crystallization was unlikely. Compared with pure Fe3O4, the characteristic peak intensities, ascribed to Fe3O4 in encapsulated microspheres, decrease which allow retention of its magnetic behavior.…”

“…These magnetic drug-containing microspheres usually consist of a magnetic core and polymeric shell. [7][8][9] For instance blending PLA with poly (ethylene glycol) (PEG) could improve hydrophilicity. 1,2 The magnetic nanoparticles (MNPs) tend to agglomerate and need to be coated with appropriate surfactants in order to create repulsion between particles and hinder agglomeration.…”

“…However PLA has poor hydrophilicity and in some applications may need to be blended with hydrophilic components. [7][8][9] For instance blending PLA with poly (ethylene glycol) (PEG) could improve hydrophilicity. 10 Doxorubicin (Dox) is a well-known anti-cancer drug that has an amphibious character that could dissolve both in aqueous and organic solvents such as methanol and chloroform.…”

Preparation, dynamic rheological behavior, crystallization, and mechanical properties of inorganic whiskers reinforced polylactic acid/hydroxyapatite nanocomposites

“…In recent years, there are more and more related investigations conducted. [17][18][19][20][21][22][23][24][25][26][27][28][29][30] For example, Jiang et al 20 investigated the influence of HA with different grain size on the crystallization behavior and mechanical property of HA/PLA composite. They found that compared with HA with small grain size range, the HA with lager grain size range is more beneficial to promotion of crystallization of PLA and can hence result in a higher mechanical property of HA/PLA composite.…”

“…They found that compared with HA with small grain size range, the HA with lager grain size range is more beneficial to promotion of crystallization of PLA and can hence result in a higher mechanical property of HA/PLA composite. Dadbin et al 25 prepared PLA/HA nanocomposite films using solution casting method and the films were then irradiated with c rays. The results showed that compared with unirradiated PLA/HA nanocomposite, the irradiated nancomposite has a PLA crystalline phase and higher tensile strength.…”