ABSTRACT
In the last few decades, hydroxyapatite (HA) has become one of the most highly prized biominerals in the biomedical industry for orthopedic and dental applications. The focus of this research was to synthesize biomimetic HA from Tridax procumbens (TP) leaf extract and investigate their antibiofilm properties. The HA was made using the sol-gel method and the HA-TP biocomposite was made by precipitation method. The d.nm size of HA and HA-TP biocomposite was determined as 193.28 and 258.14 d.nm, respectively. The zeta potential of HA and HA-TP biocomposite was determined as ?21.2 and ?18.3 mV, respectively, and found highly stable. The FTIR study revealed that phytochemicals of TP were successfully impregnated into HA-TP biocomposite. The HA and HA-TP biocomposite were found spherical and agglomerated from SEM analysis. In HR-TEM analysis, the average diameter of the HA and HA-TP biocomposite were 16.57 – 64.22 nm and 51.71 – 138.68 nm, respectively. According to the EDX analysis, HA is primarily composed of calcium, oxygen, and phosphate, whereas, HA-TP biocomposite is primarily composed of calcium, phosphate, oxygen, and carbon. In the antioxidant assay, the IC50 value (concentration required to scavenge 50% of free radicals) of HA-TP biocomposite was determined as 156.69 ± 14.02 and 180.21 ± 12.84 µg/mL in DPPH and ABTS free radical scavenging assays, respectively. The MIC (minimum inhibitory concentration) and MBC (minimum bactericidal concentration) of as-synthesized HA-TP biocomposite against Staphylococcus aureus – ATCC 13565 and Escherichia coli – MTCC 41 were observed as 181.09 ± 21.47 and 317.30 ± 41.03, and 157.59 ± 32.18 and 264.03 ± 21.58 µg/mL, respectively. The as-synthesized HA-TP biocomposite has detrimentally affected the biofilm formation of both the tested bacteria S. aureus – ATCC 13565 and E. coli – MTCC 41. The study concluded that the as-synthesized HA-TP biocomposite could be highly helpful in the biomedical field for alleviating oxidative-stress-related disorders and inhibiting microbial biofilm formation.
ABSTRACT
The present research focused on the green, non-toxic, low-cost synthesis of zinc oxide nanoparticles (ZnO NPs) using aqueous extract of Hibiscus tiliaceus leaves as a reducing and stabilizing agent. Thus, synthesized ZnO NPs were characterized by nanotechnological applications, i.e., ultraviolet-visible spectroscopy (UV-vis), dynamic light scattering (DLS), zeta potential, X-ray diffraction (XRD), Fourier transform infrared spectroscopy (FTIR), and high-resolution transmission electron microscopy (HR-TEM). The nanotechnological applications showed that as-synthesized ZnO NPs have bandgap energy of 2.97 eV, zeta potential of ?1.2 mV, crystalline in nature (JCPDS data card no-89-1397), and an average size of 30 to 60 nm. The FTIR showed that ZnO NPs have coated with plant secondary metabolites and assisted in the process of green synthesis. The ZnO NPs exhibited broad-spectrum antibacterial activity on Gram-positive and Gram-negative bacteria. The ZnO NPs showed potential anticancer activity against human breast cancer cells MCF-7 and determined the IC50 value as 65.83 ± 2.57 µg/mL by MTT assay. Furthermore, ZnO NPs were used as nano-catalyst for dye degradation of methylene blue, methyl orange, and malachite green with NABH4 as a reducing agent. The ZnO NPs exhibited potent dye degradation capability and followed pseudo-first order kinetics. The study concluded that ZnO NPs could be highly useful as anticancer and antibacterial agents in the biomedical field, and as an environmental cleaning agent for dye degradation in textile industries.