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.

Lead poisoning causes numerous clinical implications in almost all organs, with the brain, liver, and kidneys serving as the primary targets due to the abundant presence of mitochondria. Curcumin is one of the most potent constituents of Curcuma longa, which is lipophilic, phenolic and water insoluble. Curcumin is a strong antioxidant and anti-inflammatory agent in the treatments of neurodegenerative disease, cardiovascular, renal, and liver diseases, with a potential anticancer mechanism in a few clinical and experimental trials. This review will focus on the health impact of lead-induced toxicity in different organ-systems, which occurs as result of increased oxidative stress through the generation of reactive oxygen species (ROS) and reactive nitrogen species (RNS) and will discuss the therapeutic potential of curcumin against lead-induced toxicity in both human and animals.

A substantial global health burden is associated with neurotoxicity caused by lead (Pb) exposure and the common mechanism of this toxicity is mainly via oxidative damage. Curcumin has remarkable pharmacological activities but remains clinically constrained due to its poor bioavailability when orally administered. Currently, cockle shell‐derived calcium carbonate nanoparticle (CSCaCO₃NP) is gaining more acceptance in nanomedicine as a nanocarrier to various therapeutics. This study aimed at investigating the ameliorative effect of curcumin‐loaded CSCaCO₃NP (Cur‐CSCaCO₃NP) on lead‐induced neurotoxicity in rats. A total of 36 male Sprague–Dawley rats were randomly assigned into five groups. Each group consists of 6 rats apart from the control group which consists of 12 rats. During the 4 weeks induction phase, all rats received a flat dose of 50 mg/kg of lead while the control group received normal saline. The treatment phase lasted for 4 weeks, and all rats received various doses of treatments as follows: group C (Cur 100) received 100 mg/kg of curcumin, group D (Cur‐CSCaCO₃NP 50) received 50 mg/kg of Cur‐CSCaCO₃NP, and group E (Cur‐CSCaCO₃NP 100) received 100 mg/kg of Cur‐CSCaCO₃NP. The motor function test was carried out using the horizontal bar method. The cerebral and cerebellar oxidative biomarker levels were estimated using ELISA and enzyme assay kits. Lead‐administered rats revealed a significant decrease in motor scores and SOD activities with a resultant increase in MDA levels. Furthermore, marked cellular death of the cerebral and cerebellar cortex was observed. Conversely, treatment with Cur‐CSCaCO₃NP demonstrated enhanced ameliorative effects when compared with free curcumin treatment by significantly reversing the aforementioned alterations caused by lead. Thus, CSCaCO₃NP enhanced the efficacy of curcumin by ameliorating the lead‐induced neurotoxicity via enhanced attenuation of oxidative stress.