The evolution of nanomaterial in science has brought about a growing increase in nanotechnology, biomedicine, and engineering fields. This study was aimed at fabrication and characterization of conjugated gold-cockle shell-derived calcium carbonate nanoparticles (Au-CSCaCO3NPs) for biomedical application. The synthetic technique employed used gold nanoparticle citrate reduction method and a simple precipitation method coupled with mechanical use of a Programmable roller-ball mill. The synthesized conjugated nanomaterial was characterized for its physicochemical properties using transmission electron microscope (TEM), field emission scanning electron microscope (FESEM) equipped with energy dispersive X-ray (EDX) and Fourier transform infrared spectroscopy (FTIR). However, the intricacy of cellular mechanisms can prove challenging for nanomaterial like Au-CSCaCO3NPs and thus, the need for cytotoxicity assessment. The obtained spherical-shaped nanoparticles (light-green purplish) have an average diameter size of 35 ± 16 nm, high carbon and oxygen composition. The conjugated nanomaterial, also possesses a unique spectra for aragonite polymorph and carboxylic bond significantly supporting interactions between conjugated nanoparticles. The negative surface charge and spectra absorbance highlighted their stability. The resultant spherical shaped conjugated Au-CSCaCO3NPs could be a great nanomaterial for biomedical applications.

Cockle shell is an external covering of small, salt water edible clams (Anadara granosa) that dwells in coastal area. This abundant biomaterial is hard, cheap and readily available with high content of calcium carbonate in aragonite polymorphic form. At present, cockle shell-derived calcium carbonate nanoparticles (CSCaCO₃NPs) with dual applications has remarkably drawn significant attention of researchers in nanotechnology as a nanocarrier for delivery of different categories of drugs and as bone scaffold due to its beneficial potentials such as biocompatibility, osteoconductivity, pH sensitivity, slow biodegradation, hydrophilic nature and a wide safety margin. In addition, CSCaCO₃NP possesses structural porosity, a large surface area and functional group endings for electrostatic ion bonds with high loading capacity. Thus, it maintains great potential in the drug delivery system and a large number of biomedical utilisations. The pioneering researchers adopted a non-hazardous top-down method for the synthesis of CSCaCO₃NP with subsequent improvements that led to the better spherical diameter size obtained recently which is suitable for drug delivery. The method is therefore a simple, low cost and environmentally friendly, which involves little procedural steps without stringent temperature management and expensive hazardous chemicals or any carbonation methods. This paper presents a review on a few different types of nanoparticles with emphasis on the versatile most recent advancements and achievements on the synthesis and developments of CSCaCO₃NP aragonite with its applications as a nanocarrier for drug delivery in nanomedicine.

Lead (Pb) is a toxic, environmental heavy metal that induces serious clinical defects in all organs, with the nervous system being its primary target. Curcumin is the main active constituent of turmeric rhizome (Curcuma longa) with strong antioxidant and anti-inflammatory properties. This study is aimed at evaluating the therapeutic potentials of curcumin on Pb-induced neurotoxicity. Thirty-six male Sprague Dawley rats were randomly assigned into five groups with 12 rats in the control (normal saline) and 6 rats in each of groups, i.e., the lead-treated group (LTG) (50 mg/kg lead acetate for four weeks), recovery group (RC) (50 mg/kg lead acetate for four weeks), treatment group 1 (Cur100) (50 mg/kg lead acetate for four weeks, followed by 100 mg/kg curcumin for four weeks) and treatment group 2 (Cur200) (50 mg/kg lead acetate for four weeks, followed by 200 mg/kg curcumin for four weeks). All experimental groups received oral treatment via orogastric tube on alternate days. Motor function was assessed using a horizontal bar method. The cerebellar concentration of Pb was evaluated using ICP-MS technique. Pb-administered rats showed a significant decrease in motor scores and Superoxide Dismutase (SOD) activity with increased Malondialdehyde (MDA) levels. In addition, a marked increase in cerebellar Pb concentration and alterations in the histological architecture of the cerebellar cortex layers were recorded. However, treatment with curcumin improved the motor score, reduced Pb concentration in the cerebellum, and ameliorated the markers of oxidative stress, as well as restored the histological architecture of the cerebellum. The results of this study suggest that curcumin attenuates Pb-induced neurotoxicity via inhibition of oxidative stress and chelating activity.

Introduction: Curcumin has remarkable pharmacological activities but remains clinically constrained due to its poor bioavailability as a result of insolubility. This has necessitated the search for natural inorganic materials for curcumin delivery. Cockleshells are external hard materials of marine animals often treated as unwanted wastes, which are excellent sources of calcium carbonate. This study aimed to synthesize cockle shell-derived calcium carbonate (aragonite) nanoparticles (CSCaCO3NP) for delivery of curcumin and to evaluate its kinetic release in vitro. Methods: CSCaCO3NP was synthesized and conjugated with curcumin (Cur-CSCaCO3NP) using a simple top down approach and characterized for its physicochemical properties as a potential curcumin carrier. The in vitro release profile was assessed using the dialysis bag membrane method. The release data were fitted to Korsmeyer-Peppas, Zero order, and Higuchi models to evaluate the mechanism(s) of the release pattern. Results: A spherical shaped CSCaCO3NP with a surface area of 14.48+/-0.1 m2/g, with mean diameter size of 21.38+/-2.7 nm and zeta potential of -18.7 mV, was synthesized and found to have high loading content and encapsulation efficiency. The FT-IR and XRD revealed fewer observable changes on the peaks after conjugation. The profile of the in vitro kinetic release demonstrated a sustained release, and which was best fitted to the Higuchi equation model. Conclusion: The results of this study showed the capacity of the synthesized CSCaCO3NP to encapsulate curcumin efficiently with a stable release in vitro. This provides insight into and rationale for the potential of CSCaCO3NP for curcumin delivery. Therefore, CSCaCO3NP holds great prospects in the preclinical framework for enhancing curcumin efficacy in oral therapeutic applications.

Purpose: Modified top-down procedure was successfully employed in the synthesis of aragonite nanoparticles (NPs) from cheaply available natural seawater cockle shells. This was with the aim of developing a pH-sensitive nano-carrier for effective delivery of doxorubicin (DOX) on MCF-7 breast cancer cell line. Methods: The shells were cleaned with banana pelts, ground using a mortar and pestle, and stirred vigorously on a rotary pulverizing blending machine in dodecyl dimethyl betane solution. This simple procedure avoids the use of stringent temperatures and unsafe chemicals associated with NP production. The synthesized NPs were loaded with DOX to form DOX-NPs. The free and DOX-loaded NPs were characterized for physicochemical properties using field emission scanning electron microscopy, transmission electron microscopy, zeta potential analysis, Fourier transform infrared spectroscopy, and X-ray diffraction. The release profile, cytotoxicity, and cell uptake were evaluated. Results: NPs had an average diameter of 35.50 nm, 19.3% loading content, 97% encapsulation efficiency, and a surface potential and intensity of 19.1±3.9 mV and 100%, respectively. A slow and sustained pH-specific controlled discharge profile of DOX from DOX-NPs was observed, clearly showing apoptosis/necrosis induced by DOX-NPs through endocytosis. The DOX-NPs had IC₅₀ values 1.829, 0.902, and 1.0377 μg/mL at 24, 48, and 72 hrs, while those of DOX alone were 0.475, 0.2483, and 0.0723 μg/mL, respectively. However, even at higher concentration, no apparent toxicity was observed with the NPs, revealing their compatibility with MCF-7 cells with a viability of 92%. Conclusions: The modified method of NPs synthesis suggests the tremendous potential of the NPs as pH-sensitive nano-carriers in cancer management because of their pH targeting ability toward cancerous cells.

Despite the progress made in cancer treatment, difficulties are encountered with tumour targeting due to cancer structural complexity. The synthesis of homogenous calcium carbonate (CaCO₃) nanoparticles could be a carrier for doxorubicin in the management of bone cancer due to its osteoconductive and physicochemical properties with simple synthesis method to produce large scale. Among the nanocarriers, CaCO₃ nanoparticles have exhibited promising potential as targeting drug nanocarrier. The aim of this study is to synthesised and characterised doxorubicin-conjugated CaCO₃ nanoparticle (CS-CaCO₃NP-DOX), using a simple precipitation and mechanical approach to synthesise homogeneous CaCO₃NP from cockleshell. The oven-dried nanoparticles were further characterised for its physicochemical properties before and after conjugating with doxorubicin. A homogenous aragonite, spherical, porous nanocarrier was obtained with a mean diameter of 24.9 nm and zeta potential of –21 mV. The energy dispersion X-ray analysis revealed high proportion of calcium as a major element in the nanoparticle. The spectrum peak suggests little alteration upon incorporation of doxorubicin. Higher loading content and encapsulation efficiency were recorded with CS-CaCO₃NP. These properties underscore the potential of CS-CaCO₃NP in the delivery of doxorubicin, thus giving it a high potential for application in the delivery of the anticancer in the management of cancers.