Morphological and elemental mapping of gallstones using synchrotron microtomography and synchrotron X-ray fluorescence spectroscopy.

BACKGROUND AND AIM: Regional differences in gallstone (GS) composition are well documented in the Indian subcontinent. The reasons for the same are unknown. Etiopathogenesis of GS remains elusive despite advances in instrumentation. This was an in-depth analysis of the chemical, structural, and elemental composition of GS with special reference to synchroton studies. METHODS: We used high-end sensitive analytical complementary microscopic and spectroscopic methods techniques, such as X-ray diffraction, scanning electron microscopy, Fourier transform infrared, synchrotron X-ray fluorescence spectroscopy (SR-XRF), and 2D and 3D synchrotron microtomography (SR-µCT), to study the ultra structure and trace element composition of three major types of GS (cholesterol, mixed, and pigment). SR-XRF quantified the trace elements in GS. RESULTS: The cholesterol GS (monohydrate and anhydrate) were crystalline, with high calcium content. The pigment GS were amorphous, featureless, black, and fragile, with high calcium bilirubinate and carbonate salts. They had the highest concentration of iron (average 31.50 ppm) and copper (average 92.73 ppm), with bacterial inclusion. The mixed stones had features of both cholesterol and pigment GS with intermediate levels of copper (average 20.8 ppm) and iron (average 17.78 ppm). CONCLUSION: SR-µCT has, for the first time, provided cross-sectional computed imaging delineating the framework of GS and mineral distribution. It provided excellent mapping of cholesterol GS. SR-XRF confirmed that pigment GS had high concentrations of copper and iron with bacterial inclusions, the latter possibly serving as a nidus to the formation of these stones.

Design of Boron Nitride/Gelatin Electrospun Nanofibers for Bone Tissue Engineering.

Gelatin is a biodegradable biopolymer obtained by collagen denaturation, which shows poor mechanical properties. Hence, improving its mechanical properties is very essential toward the fabrication of efficient nontoxic material for biomedical applications. For this aim, various methods are employed using external fillers such as ceramics or bioglass. In this report, we introduce boron nitride (BN)-reinforced gelatin as a new class of two-dimensional biocompatible nanomaterials. The effect of the nanofiller on the mechanical behavior is analyzed. BN is efficiently exfoliated using the biopolymer gelatin as shown through Fourier transform infrared (FTIR) spectroscopy and X-ray diffraction (XRD). The exfoliated BN reinforces gelatin electrospun fibers, which results in an increase in the Young's modulus. The Electrospun Mats (ESM) are stable after the glutaraldehyde cross-linking, and the fibrous morphology is preserved. The cross-linked gelatin/BN ESM is highly bioactive in forming bonelike hydroxyapatite as shown by scanning electron microscopy. Due to their enhanced mineralization ability, the cross-linked ESM have been tested on human bone cells (HOS osteosarcoma cell line). The cell attachment, proliferation, and biocompatibility results show that the ESM are nontoxic and biodegradable. The analysis of osteoblast gene expression and the measurement of alkaline phosphatase activity confirm that these materials are suitable for bone tissue engineering.