Formulation of a Sustained Release Docetaxel Loaded Cockle Shell-Derived Calcium Carbonate Nanoparticles against Breast Cancer

Rosuvastatin/calcium carbonate co-precipitated nanoparticles: A novel synergistic approach enhancing local bone regeneration in osteoporotic rat model

This study aimed at preparing sustained release rosuvastatin (Ru) calcium carbonate (CC) co-precipitate nano-formulation for local intra-osseous application in osteoporotic rats. Nano-formulations were prepared by the co-precipitation method using different concentrations of polyvinyl alcohol (PVA) (0.2, 0.4, 0.6 %) as a stabilizer and equimolar ratios of calcium chloride and calcium carbonate (0.1, 0.3 or 0.5 M). Pre-formulation examination including; FTIR and X-ray diffraction confirmed the formation of CC nanoparticles in a crystalline structure that was preserved before and after loading with Ru. The optimized formula showing; PS of 105.71 ± 5.10 nm, PDI of 0.25 ± 0.02, ZP of -44.70 ± 0.09 mV, % EE of 60.16 ± 1.58 and a quasi-spherical nanoparticle with nano-deposition of Ru crystals adsorbed on them as seen under TEM and SEM, was then integrated in 20 % Pluronic gel. The Ru-gel exhibited good rheological behavior with a short gelation time of 20 sec and a sustained release pattern of 30 % for the optimized Ru/CC gel versus ≈ 90 % for the Ru/CC dispersion after 6 h. In-vivo, ovariectomy-induced osteoporotic rats were used to cause a bone defect in the tibial metaphysis. The drill-hole defects were then filled with the formulations under test and examined 30 days postoperatively. Through SEM-EDX scanning, histological assessments, and evaluation of bone metabolic markers, Ru/CC treatment significantly enhanced bone healing, improved bone microarchitecture, increased trabecular bone area, enhanced osteogenic gene expression, and reduced osteoclast activity. Experiments proved that Ru/CC successfully enhances osteogenesis and reduces osteoclastogenesis, proposing it as a promising therapeutic approach for enhancing bone regeneration in osteoporosis.

Organic fertilizer integrated with marine waste derived CaCO3 nanocarrier system: A focus on enhanced yield and quality in tomato cultivation

Tomatoes are rich in lycopene, β-carotene, ascorbic acid and other mineral sources including phosphorus, potassium, zinc, magnesium and iron. Major constraints in tomato cultivation were high cost, poor cultivation due to adverse weather conditions, pest attacks, microbial infections and nutritional deficiency complications. Conventional fertilizers, pesticides, fungicides and growth regulators are effective at higher concentration, which induces specific toxic effects on soil fertility, plant yield and also affects the health status of humans, animals and soil associated microbes. The use of organic fertilizers to meet the soil nutrient demand increases the acidity of soil affecting plant growth, which turned the focus of researchers towards nanofertilizer. The present study focuses on synthesis of marine waste derived CaCO3 nanoparticles formulated with azadirachtin and panchakavya emulsion to develop a CaCO3 nanofertilizer. CaCO3 nanofertilizer developed through this study was investigated for its material properties and behavioral traits. Further, the in-vitro antifungal impact of the CaCO3 nanofertilizer was examined, and it was sprayed on tomato plants via foliar spray. CaCO3 nanofertilizer effectively inhibited fusarium wilt causing plant fungal pathogen and also exhibited enhanced growth and yield of tomatoes against pest attack and nutritional deficiency with effect to foliar treatment. Also, CaCO3 nanofertilizer enhanced the total carotenoid level and essential nutritional minerals in fruit yield of tomatoes. Overall, fabricated CaCO3 nanofertilizer exhibits synergistic role of fertilizer, pesticide, fungicide and growth regulator in tomato cultivation. It suggests that, CaCO3 nanofertilizer generated from renewable biowaste will become the innovative platform for sustainable agriculture.

Natural Coptidis Rhizoma Nanoparticles Improved the Oral Delivery of Docetaxel

Purpose

Docetaxel (DTX) is a valuable anti-tumor chemotherapy drug with limited oral bioavailability. This study aims to develop an effective oral delivery system for DTX using natural nanoparticles (Nnps) derived from Coptidis Rhizoma extract.

Methods

DTX-loaded self-assembled nanoparticles (Nnps-DTX) were created using an optimized heat-induction strategy. Nnps-DTX's shape, size, Zeta potential, and in vitro stability were all carefully examined. Additionally, the study investigated the encapsulation efficiency, loading capacity, crystal form, and intermolecular interactions of DTX in Nnps-DTX. Subsequently, the solubility, release, cellular uptake, metabolic stability, and preclinical pharmacokinetics of DTX in Nnps-DTX were systematically evaluated. Finally, the cytotoxicity of Nnps-DTX was assessed in three tumor cell lines.

Results

Nnps-DTX was spherical in shape, 138.6 ± 8.2 nm in size, with a Zeta potential of -20.8 ± 0.6 mV, a DTX encapsulation efficiency of 77.6 ± 8.5%, and a DTX loading capacity of 6.8 ± 1.9%. Hydrogen bonds, hydrophobic interactions, and electrostatic interactions were involved in the formation of Nnps-DTX. DTX within Nnps-DTX was in an amorphous form, resulting in enhanced solubility (23.3 times) and release compared to free DTX. Following oral treatment, the mice in the Nnps-DTX group had DTX peak concentrations 8.8, 23.4, 44.6, and 5.7 times higher in their portal vein, systemic circulation, liver, and lungs than the mice in the DTX group. Experiments performed in Caco-2 cells demonstrated a significant increase in DTX uptake by Nnps-DTX compared to free DTX, which was significantly inhibited by indomethacin, an inhibitor of caveolae-mediated endocytosis. Furthermore, compared to DTX, DTX in Nnps-DTX demonstrated better metabolic stability in liver microsomes. Notably, Nnps-DTX significantly reduced the viability of MCF-7, HCT116, and HepG2 cells.

Conclusion

The novel self-assembled nanoparticles considerably enhanced the cellular absorption, solubility, release, metabolic stability, and pharmacokinetics of oral DTX and demonstrated strong cytotoxicity against tumor cell lines.

Long-lived enhanced magnetization-A practical metabolic MRI contrast material

Noninvasive tracking of biochemical processes in the body is paramount in diagnostic medicine. Among the leading techniques is spectroscopic magnetic resonance imaging (MRI), which tracks metabolites with an amplified (hyperpolarized) magnetization signal injected into the subject just before scanning. Traditionally, the brief enhanced magnetization period of these agents limited clinical imaging. We propose a solution based on amalgamating two materials-one having diagnostic-metabolic activity and the other characterized by robust magnetization retention. This combination slows the magnetization decay in the diagnostic metabolic probe, which receives continuously replenished magnetization from the companion material. Thus, it extends the magnetization lifetime in some of our measurements to beyond 4 min, with net magnetization enhanced by more than four orders of magnitude. This could allow the metabolic probes to remain magnetized from injection until they reach the targeted organ, improving tissue signatures in clinical imaging. Upon validation, this metabolic MRI technique promises wide-ranging clinical applications, including diagnostic imaging, therapeutic monitoring, and posttreatment surveillance.

Marine biomaterials in biomedical nano/micro-systems

Marine resources in unique marine environments provide abundant, cost-effective natural biomaterials with distinct structures, compositions, and biological activities compared to terrestrial species. These marine-derived raw materials, including polysaccharides, natural protein components, fatty acids, and marine minerals, etc., have shown great potential in preparing, stabilizing, or modifying multifunctional nano-/micro-systems and are widely applied in drug delivery, theragnostic, tissue engineering, etc. This review provides a comprehensive summary of the most current marine biomaterial-based nano-/micro-systems developed over the past three years, primarily focusing on therapeutic delivery studies and highlighting their potential to cure a variety of diseases. Specifically, we first provided a detailed introduction to the physicochemical characteristics and biological activities of natural marine biocomponents in their raw state. Furthermore, the assembly processes, potential functionalities of each building block, and a thorough evaluation of the pharmacokinetics and pharmacodynamics of advanced marine biomaterial-based systems and their effects on molecular pathophysiological processes were fully elucidated. Finally, a list of unresolved issues and pivotal challenges of marine-derived biomaterials applications, such as standardized distinction of raw materials, long-term biosafety in vivo, the feasibility of scale-up, etc., was presented. This review is expected to serve as a roadmap for fundamental research and facilitate the rational design of marine biomaterials for diverse emerging applications.

Sialic acid-decorated liposomes enhance the anti-cancer efficacy of docetaxel in tumor-associated macrophages

Tumor-associated macrophages (TAMs) in the tumor microenvironment potentially enhance tumor growth and invasion through various mechanisms and are thus an essential factor in tumor immunity. The highly expressed siglec-1 receptors on the surfaces of TAMs are potential targets for cancer drug delivery systems. Sialic acid (SA) is a specific ligand for siglec-1. In this study, the sialic acid-polyethylene glycol conjugate (DSPE-PEG2000-SA) was synthesized to modify the surface of liposomes and target TAMs by interacting with the siglec-1 receptor. Three docetaxel (DTX)-loaded liposomes, conventional (DTX-CL), DSPE-PEG2000-coated (DTX-PL), and DSPE-PEG2000-SA-coated (DTX-SAPL) liposomes, were prepared, with a particle size of <100 nm, uniform polydispersity index (PDI) values, negative zeta potential, and % encapsulation efficiency (EE) exceeding 95 %. Liposomes showed high stability after 3 months of storage at 4 °C without significant changes in particle size, PDI, zeta potential, or % EE. DTX was released from liposomes according to the Weibull model, and DTX-SAPL exhibited more rapid drug release than other liposomes. In vitro studies demonstrated that DTX-SAPL liposome exhibited a higher uptake and cytotoxicity on RAW 264.7 cells (TAM model) and lower toxicity on NIH3T3 cells (normal cell model) than other formulations. The high cell uptake ability was demonstrated by the role of the SA-SA receptor. Biodistribution studies indicated a high tumor accumulation of surface-modified liposomal formulations, particularly SA-modified liposomes, showing high signal accumulation at the tumor periphery, where TAMs were highly concentrated. Ex vivo imaging showed a significantly higher accumulation of SA-modified liposomes in the tumor, kidney, and heart than conventional liposomes. In the anti-cancer efficacy study, DTX-SAPL liposomes showed effective inhibition of tumor growth and relatively low systemic toxicity, as evidenced by the tumor volume, tumor weight, body weight values, and histopathological analysis. Therefore, DSPE-PEG2000-SA-coated liposomes could be promising carriers for DTX delivery targeting TAMs in cancer therapy.

XRD and cytotoxicity assay of submitted nanomaterial industrial samples in the Philippines

Distinct properties that nanomaterials possess compared to their bulk counterparts are attributed to their characteristic high surface area to volume ratios, and the prevalence of structure and shape effects at the nanoscale. However, these interesting properties are also accompanied by health hazards that are not seen in bulk materials. In the context of Philippine research and industry, the issue of nanosafety and the creation of nanotechnology guidelines have long been overlooked. This is of particular importance considering that nanotechnology research in the Philippines leans heavily towards medicinal and agricultural applications. In this study, nanomaterial samples from the industry submitted through the Philippine Industrial Technology Development Institute (ITDI) were analyzed using XRD and MTT cytotoxicity assay. XRD results show significant band broadening in the diffraction patterns of halloysite nanoclay, bentonite nanoparticles, silver nanoparticles, and CaCO3 nanoparticles, indicating that samples were in the nanometer range. The diffraction pattern of TiO2, however, did not exhibit band broadening, which may be due to the tendency of TiO2 nanoparticles to aggregate. Submitted samples were also assessed for their effect on cell viability using MTT cytotoxicity assay. Among these samples, only silver nanoparticles exhibited cytotoxicity to the AA8 cell line.

Nanoformulations - Insights Towards Characterization Techniques

BACKGROUND

Drug-loaded novel nanoformulations are gaining importance due to their versatile properties compared to conventional pharmaceutical formulations. Nanomaterials, apart from their multifactorial benefits, have a wider scope in the prevention, treatment, and diagnosis of cancer. Understanding the chemistry of drug-loaded nano-formulations to elicit its behaviour both at molecular and systemic levels is critical in the present scenario. Drug-loaded nanoformulations are controlled by their size, shape, surface chemistry, and release behavior. The major pharmaceutical drug loaded nanocarriers reported for anticancer drug delivery for the treatment of various forms of cancers such as lung cancer, liver cancer, breast cancer, colon cancer, etc include nanoparticles, nanospheres, nanodispersions, nanocapsules, nanomicelles, cubosomes, nanoemulsions, liposomes and niosomes. The major objectives in designing anticancer drug-loaded nanoformulations are to manage the particle size/morphology correlating with the drug release to fulfil the specific objectives. Hence, nano characterizations are very critical both at in vitro and in vivo levels.

OBJECTIVE

The main objective of this review paper is to summarise the major characterization techniques used for the characterization of drug-loaded nanoformulations. Even though information on characterization techniques of various nano-formulations is available in the literature, it is scattered. The proposed review will provide a comprehensive understanding of nanocharacterization techniques.

CONCLUSION

To conclude, the proposed review will provide insights towards the different nano characterization techniques along with their recent updates, such as particle size, zeta potential, entrapment efficiency, in vitro release studies (chromatographic HPLC, HPTLC, and LC-MS/MS analysis), EPR analysis, X-ray diffraction analysis, thermal analysis, rheometric, morphological analysis etc. Additionally, the challenges encountered by the nano characterization techniques will also be discussed.

Effect of different molecular weight and terminal group PLGA on docetaxel nanoparticles: Characterization and cytotoxic activity of castration-resistant prostate cancer cells

The choice of polymer and its compatibility with drug used determine the fate of nanoparticle in therapy. There has been limited sources about effect of resomer differentiation in nanoparticle related with physical and chemical properties and also biological activities of product. Therefore, we aimed to formulate docetaxel loaded polylactic-co-glycolic acid nanoparticles with different molecular weights (Resomer 502 and 504) and terminal groups (Resomer 502H and 504H) and to investigate the effect of these resomers on nanoparticle character, prostate cancer and healthy cells. Docetaxel loaded PLGA nanoparticles were prepared by single emulsion solvent evaporation method. Surface characterizations were carried out by zeta sizer and scanning electron microscopy. Encapsulation efficiency, in vitro drug release profiles and cytotoxic activity were determined. Main effect on the surface morphology of nanoparticles was the molecular weight of the polymer. In groups with acid terminal function have higher encapsulation and reaction efficiency. In all formulations, in vitro release was observed after 334 hours at pH 7.4 and 240 hours at pH 5.6. Also, the groups with high molecular weight showed selective cytotoxicity. These resomers especially RG 504 and RG 504H have potential to be used as a low-dose and high-efficiency extended-release drug delivery system in the treatment of prostate cancer.

Lung cancer targeting efficiency of Silibinin loaded Poly Caprolactone /Pluronic F68 Inhalable nanoparticles: In vitro and In vivo study

Silibinin (SB) is shown to have an anticancer properties. However, its clinical therapeutic effects have been restricted due to its low water solubility and poor absorption after oral administration. The aim of this study was to develop SB-loaded PCL/Pluronic F68 nanoparticles for pulmonary delivery in the treatment of lung cancer. A modified solvent displacement process was used to make nanoparticles, which were then lyophilized to make inhalation powder, Nanoparticles were characterized with DSC, FTIR,SEM and In vitro release study. Further, a validated HPLC method was developed to investigate the Biodistribution study, pharmacokinetic parameters. Poly Caprolactone PCL / Pluronic F68 NPs showed the sustained release effect up to 48 h with an emitted (Mass median Aerodynamic diameter)MMAD and (Geometric size distribution)GSD were found to be 4.235 ±0.124 and 1.958±1.23 respectively. More specifically, the SB Loaded PCL/Pluronic F 68 NPs demonstrated long circulation and successful lung tumor-targeting potential due to their cancer-targeting capabilities. SB Loaded PCL/Pluronic F68 NPs significantly inhibited tumour growth in lung cancer-induced rats after inhalable administration. In a pharmacokinetics study, PCL/ Pluronic F68 NPs substantially improved SB bioavailability, with a more than 4-fold rise in AUC when compared to IV administration. These findings indicate that SB-loaded PCL/PluronicF68 nanoparticles may be a successful lung cancer therapy delivery system.

Hard, Soft, and Hard-and-Soft Drug Delivery Carriers Based on CaCO3 and Alginate Biomaterials: Synthesis, Properties, Pharmaceutical Applications

Because free therapeutic drug molecules often have adverse effects on normal tissues, deliver scanty drug concentrations and exhibit a potentially low efficacy at pathological sites, various drug carriers have been developed for preclinical and clinical trials. Their physicochemical and toxicological properties are the subject of extensive research. Inorganic calcium carbonate particles are promising candidates as drug delivery carriers owning to their hardness, porous internal structure, high surface area, distinctive pH-sensitivity, low degradability, etc, while soft organic alginate hydrogels are also widely used because of their special advantages such as a high hydration, bio-adhesiveness, and non-antigenicity. Here, we review these two distinct substances as well as hybrid structures encompassing both types of carriers. Methods of their synthesis, fundamental properties and mechanisms of formation, and their respective applications are described. Furthermore, we summarize and compare similarities versus differences taking into account unique advantages and disadvantages of these drug delivery carriers. Moreover, rational combination of both carrier types due to their performance complementarity (yin-&yang properties: in general, yin is referred to for definiteness as hard, and yang is broadly taken as soft) is proposed to be used in the so-called hybrid carriers endowing them with even more advanced properties envisioned to be attractive for designing new drug delivery systems.

Supramolecular lipid nanoparticles as delivery carriers for non-invasive cancer theranostics

Nanotheranostics is an emerging frontier of personalized medicine research particularly for cancer, which is the second leading cause of death. Supramolecular aspects in theranostics are quite allured to achieve more regulation and controlled features. Supramolecular nanotheranostics architecture is focused on engineering of modular supramolecular assemblies benefitting from their mutable and stimuli-responsive properties which confer an ultimate potential for the fabrication of unified innovative nanomedicines with controlled features. Amalgamation of supramolecular approaches to nano-based features further equip the potential of designing novel approaches to overcome limitations seen by the conventional theranostic strategies, for curing even the lethal diseases and endowing personalized therapeutics with optimistic prognosis, endorsing their clinical translation. Among many potential nanocarriers for theranostics, lipid nanoparticles (LNPs) have shown various promising advances in theranostics and their formulation can be tailored for several applications. Despite the great advancement in cancer nanotheranostics, there are still many challenges that need to be highlighted to fill the literature gap. For this purpose, herein, we have presented a systematic overview on the subject and proposed LNPs as the potential material to manage cancer via non-invasive approaches by highlighting the use of supramolecular approaches to make them robust for cancer theranostics. We have concluded the review by entailing the future perspectives of lipid nanotheranostics towards clinical translation.

Synthesis and Characterization of Gefitinib and Paclitaxel Mono and Dual Drug-Loaded Blood Cockle Shells (Anadara granosa)-Derived Aragonite CaCO3 Nanoparticles

Calcium carbonate has slowly paved its way into the field of nanomaterial research due to its inherent properties: biocompatibility, pH-sensitivity, and slow biodegradability. In our efforts to synthesize calcium carbonate nanoparticles (CSCaCO₃NP) from blood cockle shells (Anadara granosa), we developed a simple method to synthesize CSCaCO₃NP, and loaded them with gefitinib (GEF) and paclitaxel (PTXL) to produce mono drug-loaded GEF-CSCaCO₃NP, PTXL-CSCaCO₃NP, and dual drug-loaded GEF-PTXL-CSCaCO₃NP without usage of toxic chemicals. Fourier-transform infrared spectroscopy (FTIR) results reveal that the drugs are bound to CSCaCO₃NP. Scanning electron microscopy studies reveal that the CSCaCO₃NP, GEF-CSCaCO₃NP, PTXL-CSCaCO₃NP, and GEF-PTXL-CSCaCO₃NP are almost spherical nanoparticles, with a diameter of 63.9 ± 22.3, 83.9 ± 28.2, 78.2 ± 26.4, and 87.2 ± 26.7 (nm), respectively. Dynamic light scattering (DLS) and N₂ adsorption-desorption experiments revealed that the synthesized nanoparticles are negatively charged and mesoporous, with surface areas ranging from ~8 to 10 (m²/g). Powder X-ray diffraction (PXRD) confirms that the synthesized nanoparticles are aragonite. The CSCaCO₃NP show excellent alkalinization property in plasma simulating conditions and greater solubility in a moderately acidic pH medium. The release of drugs from the nanoparticles showed zero order kinetics with a slow and sustained release. Therefore, the physico-chemical characteristics and in vitro findings suggest that the drug loaded CSCaCO₃NP represent a promising drug delivery system to deliver GEF and PTXL against breast cancer.

Novel Gellan Gum-Based In Situ Nanovesicle Formulation of Docetaxel for Its Localized Delivery Using Depot Formation

In the present study, different in situ hydrogel formulations of docetaxel (DTX) based on biocompatible polymers such as Hyaluronic Acid (HA), poloxamer-407, chitosan and gellan gum were formulated to increase its therapeutic efficacy and reduce toxicity. DTX was loaded in nanovesicles (20 mg/mL equivalent to commercial strength) and further incorporated into the hydrogel bases to possess a dual rationale of protection against burst release and enhanced solubility of the drug. The optimized hydrogel formulation (NV-TPGS-3-GG-4) showed ideal rheological behavior and in situ characteristics at 37±0.5°C with sustained release of more than 144 h. The optimized formulation had instant in vitro gelation (2.8±0.3 min) with good injectability in comparison to the conventional commercial DTX injectable formulation having instant release (<2 h). Additionally, developed formulation exhibited an improved biodisponibility (25.1±0.2 h) in comparison to the commercially available formulation (1.7±0.1 h). The Solid Tumor Carcinoma model in Swiss albino mice revealed that the optimized formulation (based on gellan gum) showed better tumor reduction (85.7±1.2%) and lower toxicity as compared to the commercial formulation (77.3±1.3%). Pharmacokinetic and biodistribution studies demonstrated 3 to 4 times higher localization of drug in tumors. Our findings suggested that injectable gellan gum-based in situ hydrogel formulation can be an effective delivery system for DTX with enhanced solubility, reduced toxicity, and better targeting to the tumors for improved therapeutics.Graphical abstract.

Enhanced Cytotoxic Activity of Docetaxel-Loaded Silk Fibroin Nanoparticles against Breast Cancer Cells

Despite decades of research, breast cancer therapy remains a great challenge. Docetaxel is an antimicrotubule agent that is effectively used for the treatment of breast cancer. However, its clinical use is significantly hampered by its low water solubility and systemic toxicity. The current study was designed to prepare docetaxel (DXL)-loaded silk-fibroin-based nanoparticles (SF-NPs) and to screen their potential antitumor activity against breast cancer cell lines. DXL-loaded SF-NPs were prepared using a nanoprecipitation technique and were evaluated for particle size, zeta potential, entrapment efficiency, and in vitro release profile. In addition, DXL-loaded SF-NPs were screened for in vitro cytotoxicity, cellular uptake, and apoptotic potential against MCF-7 and MDA-MB-231 breast cancer cell lines. The prepared DXL-loaded SF-NPs were 178 to 198 nm in diameter with a net negative surface charge and entrapment efficiency ranging from 56% to 72%. In vitro release studies exhibited a biphasic release profile of DXL from SF-NPs with sustained drug release for 72 h. In vitro cell studies revealed that entrapment of DXL within SF-NPs significantly improved cytotoxic potential against breast cancer cell lines, compared to the free drug, and enhanced cellular uptake of DXL by breast cancer cells. Furthermore, the accumulation in the G2/M phase was significantly higher in cells treated with DXL-loaded SF-NPs than in cells treated with free DXL. Collectively, the superior antitumor activities of DXL-loaded SF-NPs against breast cancer cells, compared to free DXL, could be ascribed to improved apoptosis and cell cycle arrest. Our results highlighted the feasibility of using silk fibroin nanoparticles as a nontoxic biocompatible delivery vehicle for enhanced therapeutic outcomes in breast cancer.

Wheat Germ Agglutinin-Conjugated Disulfide Cross-Linked Alginate Nanoparticles as a Docetaxel Carrier for Colon Cancer Therapy

PURPOSE

In chemotherapy, oral administration of drug is limited due to lack of drug specificity for localized colon cancer cells. The inability of drugs to differentiate cancer cells from normal cells induces side effects. Colonic targeting with polymeric nanoparticulate drug delivery offers high potential strategies for delivering hydrophobic drugs and fewer side effects to the target site. Disulfide cross-linked polymers have recently acquired high significance due to their potential to degrade in reducing colon conditions while resisting the upper gastrointestinal tract's hostile environment. The goal of this project is, therefore, to develop pH-sensitive and redox-responsive fluorescein-labeled wheat germ agglutinin (fWGA)-mounted disulfide cross-linked alginate nanoparticles (fDTP2) directly targeting docetaxel (DTX) in colon cancer cells.

METHODS

fDTP2 was prepared by mounting fWGA on DTX-loaded nanoparticles (DTP2) using the two-step carbodiimide method. Morphology of fDTP2 was examined using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Dynamic light scattering (DLS) study was carried out to determine the mean diameter, polydispersity index (PDI) and zeta potential of fDTP2. Cellular uptake efficiency was examined using fluorescence microplate reader. Biocompatibility and active internalization of fDTP2 were conducted on HT-29.

RESULTS

fDTP2 was found to exhibit a DTX loading efficiency of 19.3%. SEM and TEM tests revealed spherical nanoparticles. The in vitro DTX release test showed a cumulative release of 54.7%. From the DLS study, fDTP2 reported a 277.7 nm mean diameter with PDI below 0.35 and -1.0 mV zeta potential. HT-29 which was fDTP2-treated demonstrated lower viability than L929 with a half maximal inhibitory concentration (IC50) of 34.7 µg/mL. HT-29 (33.4%) internalized fDTP2 efficiently at 2 h incubation. The study on HT-29 active internalization of nanoparticles through fluorescence and confocal imaging indicated such.

CONCLUSION

In short, fDTP2 demonstrated promise as a colonic drug delivery DTX transporter.

Efficient synthesis strategy of folate-modified carboxymethyl chitosan/CaCO3 hybrid nanospheres and their drug-carrying and sustained release properties

Folate-modified carboxymethyl chitosan (FCMC) was made by folate acid as targeted group and attaching folate to carboxymethyl chitosan, and then, targeted FCMC/CaCO₃ hybrid nanosphere were formed by self-assembly of calcium carbonate in FCMC solution. The physicochemical properties of the nanospheres were investigated by Fourier transform infrared spectroscopy, X-ray diffraction analysis, Brunauer-Emmett-Teller measurement and thermogravimetric analysis (TGA). The results showed that the FCMC/CaCO₃ hybrid nanospheres were composed of calcite, vaterite and polysaccharides, and the content of organic compounds was 12.17%. Also, the structure performance of the hybrid nanospheres was analyzed. Besides, the effects of the hybrid nanospheres on the encapsulation efficiency, the drug loading content and the release behavior were also analyzed with the metformin (MET) as a model drug. Scanning electron microscope, Zeta potential analysis and UV-Vis were used to characterize the hybrid nanospheres. Under the conditions of FCMC/Ca²⁺ molar ratio of 4: 1 and reaction for 24 h, the achieved results showed that the spherical aggregates with regular morphology were obtained and the average particle size of the nanospheres was 207 nm. The specific surface area of the hybrid nanosphere is 27.06 m²·g^-1 and the average pore diameter of the sample is 3.84 nm, indicating the presence of mesoporous structure in the sample. This mesoporous structure can supply potential space for adsorption of anticancer drugs. Additionally, the surface charge of the nanoparticles was positive and the entrapment efficiency was 83.32%. The hybrid nanospheres have a capability of effective pH-sensitivity controlled drug release. All the drug loaded hybrid nanospheres successfully sustained the release of MET at pH 7.4, only about 44.58% of the drug released in 6 days. While under acidic condition (pH 5.0) drug release was significantly accelerated, being over 98.85% of the drug released. The hybrid nanospheres demonstrated an excellent smart drug delivery behavior.

Extracellular vesicle mimics made from iPS cell-derived mesenchymal stem cells improve the treatment of metastatic prostate cancer

BACKGROUND

Extracellular vesicles (EVs) and their mimics from mesenchymal stem cells (MSCs) are promising drug carriers to improve cancer treatment, but their application is hindered by donor variations and expansion limitations of conventional tissue-derived MSCs. To circumvent these issues, we made EV-mimicking nanovesicles from standardized MSCs derived from human induced pluripotent stem cells (iPSCs) with a theoretically limitless expandability, and examined the targeting capacity of these nanovesicles to prostate cancer.

METHODS

Nanovesicles are made from intact iPSC-MSCs through serial extrusion. The selective uptake of fluorescently labeled nanovesicles by prostate cancer cells vs. non-tumor cells was examined with flow cytometry. For in vivo tracing, nanovesicles were labeled with fluorescent dye DiR or renilla luciferase. In mice carrying subcutaneous or bone metastatic PC3 prostate cancer, the biodistribution of systemically infused nanovesicles was examined with in vivo and ex vivo imaging of DiR and luminescent signals. A chemotherapeutic drug, docetaxel, was loaded into nanovesicles during extrusion. The cytotoxicities of nanovesicle-encapsulated docetaxel on docetaxel-sensitive and -resistant prostate cancer cells and non-tumor cells were examined in comparison with free docetaxel. Therapeutic effects of nanovesicle-encapsulated docetaxel were examined in mice carrying subcutaneous or bone metastatic prostate cancer by monitoring tumor growth in comparison with free docetaxel.

RESULTS

iPSC-MSC nanovesicles are more selectively taken up by prostate cancer cells vs. non-tumor cells in vitro compared with EVs, membrane-only EV-mimetic nanoghosts and liposomes, which is not affected by storage for up to 6 weeks. In mouse models of subcutaneous and bone metastatic PC3 prostate cancer, systemically infused nanovesicles accumulate in tumor regions with significantly higher selectivity than liposomes. The loading of docetaxel into nanovesicles was efficient and did not affect the selective uptake of nanovesicles by prostate cancer cells. The cytotoxicities of nanovesicle-encapsulated docetaxel are significantly stronger on docetaxel-resistant prostate cancer cells and weaker on non-tumor cells than free docetaxel. In mouse models of subcutaneous and bone metastatic prostate cancer, nanovesicle-encapsulated docetaxel significantly decreased the tumor growth and toxicity to white blood cells compared with free docetaxel.

CONCLUSIONS

Our data indicate that EV-mimicking iPSC-MSC nanovesicles are promising to improve the treatment of metastatic prostate cancer.

Cockle shell-derived aragonite calcium carbonate nanoparticle for targeting cancer and breast cancer stem cells

Cockle shell-derived aragonite calcium carbonate nanoparticles (CACNP) have demonstrated prospect as nano-sized drug carriers for targeting cancer cells. CACNP is biocompatible, biodegradable and its biomaterial is readily available and is of low cost. In addition, CACNP is highly porous, has a large surface area which confer a high loading capacity. The pH-dependent release properties as well as its potential for surface functionalization with targeting agents make CACNP useful in passive and active targeting of cancer cells and cancer stem cells. In this article, we reviewed the current state of CACNP as nano-sized drug carrier for targeting cancer cells, cancer stem cells and its biocompatibility.

Lactoferrin-dual drug nanoconjugate: Synergistic anti-tumor efficacy of docetaxel and the NF-κB inhibitor celastrol

Despite the progress in cancer nanotherapeutics, some obstacles still impede the success of nanocarriers and hinder their clinical translation. Low drug loading, premature drug release, off-target toxicity and multi-drug resistance are among the most difficult challenges. Lactoferrin (LF) has demonstrated a great tumor targeting capacity via its high binding affinity to low density lipoprotein (LDL) and transferrin (Tf) receptors overexpressed by various cancer cells. Herein, docetaxel (DTX) and celastrol (CST) could be successfully conjugated to LF backbone for synergistic breast cancer therapy. Most importantly, the conjugate self-assembled forming nanoparticles of 157.8 nm with elevated loading for both drugs (6.94 and 5.98% for DTX and CST, respectively) without risk of nanocarrier instability. Moreover, the nanoconjugate demonstrated enhanced in vivo anti-tumor efficacy in breast cancer-bearing mice, as reflected by a reduction in tumor volume, prolonged survival rate and significant suppression of NF-κB p65, TNF-α, COX-2 and Ki-67 expression levels compared to the group given free combined DTX/CST therapy and to positive control. This study demonstrated the proof-of-principle for dual drug coupling to LF as a versatile nanoplatform that could augment their synergistic anticancer efficacy.

Pharmacokinetics of Free Oxytetracycline and Oxytetracycline Loaded Cockle Shell Calcium Carbonate-Based Nanoparticle in BALB/c Mice

The development and utilization of nano-antibiotics is currently gaining attention as a possible solution to antibiotic resistance. The aim of this study was therefore to determine the pharmacokinetics of free oxytetracycline (OTC) and oxytetracycline loaded cockle shell calcium carbonate-based nanoparticle (OTC-CNP) after a single dose of intraperitoneal (IP) administration in BALB/c mice. A total of 100 female BALB/c mice divided into two groups of equal number (n = 50) were administered with 10 mg/kg OTC and OTC-CNP, respectively. Blood samples were collected before and post-administration from both groups at time 0, 5, 10, 15, and 30 min and 1, 2, 6, 24, and 48 h, and OTC plasma concentration was quantified using a validated HPLC-UV method. The pharmacokinetic parameters were analyzed using a non-compartment model. The C _max values of OTC in OTC-CNP and free OTC treated group were 64.99 and 23.53 μg/ml, respectively. OTC was detected up to 24 h in the OTC-CNP group as against 1 h in the free OTC group following intraperitoneal administration. In the OTC-CNP group, the plasma elimination rate of OTC was slower while the half-life, the area under the curve, and the volume of the distribution were increased. In conclusion, the pharmacokinetic profile of OTC in the OTC-CNP group differs significantly from that of free OTC. However, further studies are necessary to determine the antibacterial efficacy of OTC-CNP for the treatment of bacterial diseases.

Curcumin-loaded cockle shell-derived calcium carbonate nanoparticles: A novel strategy for the treatment of lead-induced hepato-renal toxicity in rats

Lead (Pb) toxicity affects the hepatic and renal systems resulting to homeostasis imbalance. Curcumin is a strong antioxidant but has restrained clinical applications due to its poor bioavailability. Nanomedicine showed promising potentials in drug delivery and has brought forth the use of cockle shell-derived aragonite calcium carbonate nanoparticles (CSCaCO₃NP) to enhance the effectiveness and targeted delivery of curcumin (Cur). Thus, this study aimed at evaluating the therapeutic effect of curcumin-loaded CSCaCO₃NP (Cur- CSCaCO₃NP) on lead-induced hepato-renal toxicity in rats. Thirty-six male adults Sprague-Dawley rats were randomly assigned into five groups. All groups contained six rats each except for group A, which contained 12 rats. All rats apart from the rats in group A (control) were orally administered a flat dose of 50 mg/kg of lead for four weeks. Six rats from group A and B were euthanized after four weeks of lead induction. Oral administration of curcumin (100 mg/kg) for group C and Cur-CSCaCO₃NP (50 and 100 mg/kg) for groups D and E respectively, commenced immediately after 4 weeks of lead induction which lasted for 4 weeks. All rats were euthanized at the 8th week of the experiment. Further, biochemical, histological and hematological analysis were performed. The findings revealed a biochemical, hematological and histological changes in lead-induced rats. However, treatments with the Cur-CSCaCO₃NP and free curcumin reversed the aforementioned changes. Although, Cur-CSCaCO₃NP presented better therapeutic effects on lead-induced toxicity in rats when compared to free curcumin as there was significant improvements in hematological, biochemical and histological changes which is parallel with attenuation of oxidative stress. The findings of the current study hold great prospects for Cur-CSCaCO₃NP as a novel approach for effective oral treatment of lead-induced hepato-renal impairments.

Novel Drug Delivery Systems for Loading of Natural Plant Extracts and Their Biomedical Applications

Many types of research have distinctly addressed the efficacy of natural plant metabolites used for human consumption both in cell culture and preclinical animal model systems. However, these in vitro and in vivo effects have not been able to be translated for clinical use because of several factors such as inefficient systemic delivery and bioavailability of promising agents that significantly contribute to this disconnection. Over the past decades, extraordinary advances have been made successfully on the development of novel drug delivery systems for encapsulation of plant active metabolites including organic, inorganic and hybrid nanoparticles. The advanced formulas are confirmed to have extraordinary benefits over conventional and previously used systems in the manner of solubility, bioavailability, toxicity, pharmacological activity, stability, distribution, sustained delivery, and both physical and chemical degradation. The current review highlights the development of novel nanocarrier for plant active compounds, their method of preparation, type of active ingredients, and their biomedical applications.

Docetaxel-loaded solid lipid nanoparticles prevent tumor growth and lung metastasis of 4T1 murine mammary carcinoma cells

BACKGROUND

Metastasis causes the most breast cancer-related deaths in women. Here, we investigated the antitumor effect of solid lipid nanoparticles (SLN-DTX) when used in the treatment of metastatic breast tumors using 4T1-bearing BALB/c mice.

RESULTS

Solid lipid nanoparticles (SLNs) were produced using the high-energy method. Compritol 888 ATO was selected as the lipid matrix, and Pluronic F127 and Span 80 as the surfactants to stabilize nanoparticle dispersion. The particles had high stability for at least 120 days. The SLNs' dispersion size was 128 nm, their polydispersity index (PDI) was 0.2, and they showed a negative zeta potential. SLNs had high docetaxel (DTX) entrapment efficiency (86%), 2% of drug loading and showed a controlled drug-release profile. The half-maximal inhibitory concentration (IC₅₀) of SLN-DTX against 4T1 cells was more than 100 times lower than that of free DTX after 24 h treatment. In the cellular uptake test, SLN-DTX was taken into the cells significantly more than free DTX. The accumulation in the G2-M phase was significantly higher in cells treated with SLN-DTX (73.7%) than in cells treated with free DTX (23.0%), which induced subsequent apoptosis. TEM analysis revealed that SLN-DTX internalization is mediated by endocytosis, and fluorescence microscopy showed DTX induced microtubule damage. In vivo studies showed that SLN-DTX compared to free docetaxel exhibited higher antitumor efficacy by reducing tumor volume (p < 0.0001) and also prevented spontaneous lung metastasis in 4T1 tumor-bearing mice. Histological studies of lungs confirmed that treatment with SLN-DTX was able to prevent tumor. IL-6 serum levels, ki-67 and BCL-2 expression were analyzed and showed a remarkably strong reduction when used in a combined treatment.

CONCLUSIONS

These results indicate that DTX-loaded SLNs may be a promising carrier to treat breast cancer and in metastasis prevention.

Docetaxel-Loaded Disulfide Cross-Linked Nanoparticles Derived from Thiolated Sodium Alginate for Colon Cancer Drug Delivery

In this study, fluorescein-labelled wheat germ agglutinin (fWGA)-conjugated disulfide cross-linked sodium alginate nanoparticles were developed to specifically target docetaxel (DTX) to colon cancer cells. Different amounts of 3-mercaptopropionic acid (MPA) were covalently attached to sodium alginate to form thiolated sodium alginate (MPA1-5). These polymers were then self-assembled and air-oxidised to form disulfide cross-linked nanoparticles (MP1-5) under sonication. DTX was successfully loaded into the resulting MP1-5 to form DTX-loaded nanoparticles (DMP1-5). DMP2 had the highest loading efficiency (17.8%), thus was chosen for fWGA surface conjugation to form fWGA-conjugated nanoparticles (fDMP2) with a conjugation efficiency of 14.1%. Transmission electron microscopy (TEM) and scanning electron microscopy (SEM) analyses showed spherical nanoparticles, and an in vitro drug release study recorded a cumulative drug release of 48.6%. Dynamic light scattering (DLS) analysis revealed a mean diameter (MD) of 289 nm with a polydispersity index (PDI) of 0.3 and a zeta potential of -2.2 mV for fDMP2. HT-29 human colon cancer cells treated with fDMP2 showed lower viability than that of L929 mouse fibroblast cells. These results indicate that fDMP2 was efficiently taken up by HT-29 cells (29.9%). Fluorescence and confocal imaging analyses also showed possible internalisation of nanoparticles by HT-29 cells. In conclusion, fDMP2 shows promise as a DTX carrier for colon cancer drug delivery.

Ionically Cross-Linked Chitosan Nanoparticles for Sustained Delivery of Docetaxel: Fabrication, Post-Formulation and Acute Oral Toxicity Evaluation

Introduction

Polymeric nanoparticles are potential carriers for the efficient delivery of hydrophilic and hydrophobic drugs due to their multifaceted applications. Docetaxel is relatively less hydrophobic and twice as potent as paclitaxel. Like other taxane chemotherapeutic agents, docetaxel is not well tolerated and shows toxicity in the patients. Nanoencapsulation of potent chemotherapeutic agents has been shown to improve tolerability and therapeutic outcome. Therefore, the present study was designed to fabricate chitosan and sodium tripolyphosphate (STPP) based on ionically cross-linked nanoparticles for sustained release of docetaxel.

Methods

Nanoparticles were prepared by the ionic-gelation method by dropwise addition of the STPP solution into the chitosan solution in different ratios. CNPs were characterized for post-formulation parameters like size, zeta potential, scanning electron microscope (SEM), FTIR, DSC/TGA, pXRD, and in-vitro drug release, as well as for acute oral toxicity studies in Wistar rats.

Results and discussion

The optimized docetaxel loaded polymeric nanoparticles were in the size range (172.6nm–479.65 nm), and zeta potential (30.45–35.95 mV) required to achieve enhanced permeation and retention effect. In addition, scanning electron microscopy revealed rough and porous surface, whereas, FTIR revealed the compatible polymeric nanoparticles. Likewise, the thermal stability was ensured through DSC and TG analysis, and powder X-ray diffraction analysis exhibited solid-state stability of the docetaxel loaded nanoparticles. The in-vitro drug release evaluation in phosphate buffer saline (pH 7.4) showed sustained release pattern, i.e. 51.57–69.93% within 24 hrs. The data were fitted to different release kinetic models which showed Fickian diffusion as a predominant release mechanism (R²= 0.9734–0.9786, n= 0.264–0.340). Acceptable tolerability was exhibited by acute oral toxicity in rabbits and no abnormality was noted in growth, behavior, blood biochemistry or histology and function of vital organs.

Conclusion

Ionically cross-linked chitosan nanoparticles are non-toxic and biocompatible drug delivery systems for sustained release of chemotherapeutic agents, such as docetaxel.

Cockle Shell-Derived Calcium Carbonate (Aragonite) Nanoparticles: A Dynamite to Nanomedicine

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.

Modified methods of nanoparticles synthesis in pH-sensitive nano-carriers production for doxorubicin delivery on MCF-7 breast cancer cell line

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.

Docetaxel-loaded human serum albumin (HSA) nanoparticles: synthesis, characterization, and evaluation

Background

Docetaxel (DTX) is an anticancer drug that is currently formulated with polysorbate 80 and ethanol (50:50, v/v) in clinical use. Unfortunately, this formulation causes hypersensitivity reactions, leading to severe side-effects, which have been primarily attributed to polysorbate 80.

Methods

In this study, a DTX-loaded human serum albumin (HSA) nanoparticle (DTX-NP) was designed to overcome the hypersensitivity reactions that are induced by polysorbate 80. The methods of preparing the DTX-NPs have been optimized based on factors including the drug-to-HSA weight ratio, the duration of HSA incubation, and the choice of using a stabilizer. Synthesized DTX-NPs were characterized with regard to their particle diameters, drug loading capacities, and drug release kinetics. The morphology of the DTX-NPs was observed via scanning electron microscopy (SEM) and the successful preparation of DTX-NPs was confirmed via differential scanning calorimetry (DSC). The cytotoxicity and cellular uptake of DTX-NPs were investigated in the non-small cell lung cancer cell line A549 and the maximum tolerated dose (MTD) of DTX-NPs was evaluated via investigations with BALB/c mice.

Results

The study showed that the loading capacity and the encapsulation efficiency of DTX-NPs prepared under the optimal conditions was 11.2 wt% and 63.1 wt%, respectively and the mean diameter was less than 200 nm, resulting in higher permeability and controlled release. Similar cytotoxicity against A549 cells was exhibited by the DTX-NPs in comparison to DTX alone while higher maximum tolerated dose (MTD) with the DTX-NPs (75 mg/kg) than with DTX (30 mg/kg) was demonstrated in mice, suggesting that the DTX-NPs prepared with HSA yielded similar anti-tumor activity but were accompanied by less systemic toxicity than solvent formulated DTX.

Conclusions

DTX-NPs warrant further investigation and are promising candidates for clinical applications.

Evaluation of a self-nanoemulsifying docetaxel delivery system

A self-nanoemulsifying drug delivery system (SNEDDS) was developed as a novel route to enhance the efficacy of docetaxel lipophilic drug. SNEDDS comprised ethyl oleate, Tween 80 and poly(ethylene glycol) 600, as oil, surfactant and co-surfactant, and formed stabilized monodispersed oil nanodroplets upon dilution in water. SNEDDS represented encapsulation efficiency and loading capacity of 21.4 and 52.7%, respectively. The docetaxel release profile from the drug-loaded SNEDDS was recorded, its effectiveness against MCF-7 cell line was investigated, and an IC₅₀ value of 0.98 ± 0.05 μg mL^-1 was attained. The drug-loaded SNEDDS was administrated in rats, and the pharmacokinetic parameters of maximum concentration of 22.2 ± 0.8 μg mL^-1, time to attain this maximum concentration of 230 min, and area under the curve of 1.71 ± 0.18 μg min mL^-1 were obtained. The developed SNEDDS formulation can be represented as an alternative to docetaxel administration.

Toxicity and Safety Evaluation of Doxorubicin-Loaded Cockleshell-Derived Calcium Carbonate Nanoparticle in Dogs

Doxorubicin (DOX) is a potent anticancer agent with cytotoxic effects which limit its clinical usage. This effect is due to its nonselective nature causing injury to the cells as a result of reactive free oxygen radical's release. Cockleshell-derived calcium carbonate nanoparticle (CS-CaCO3NP) is a pH-responsive carrier with targeted delivery potentials. This study aimed at evaluating the toxicity effects of repeated dose administration of DOX-loaded CS-CaCO3NP in healthy dogs. Fifteen dogs with an average body weight of 15 kg were randomized equally into 5 groups. Dogs were subjected to 5 doses at every 3-week interval with (i) normal saline, (ii) DOX, 30 mg/m2, and the experimental groups: CS-CaCO3NP-DOX at (iii) high dose, 50 mg/m2, (iv) clinical dose, 30 mg/m2, and (v) low dose, 20 mg/m2. Radiographs, electrocardiography, and blood samples were collected before every treatment for haematology, serum biochemistry, and cardiac injury assessment. Heart and kidney tissues were harvested after euthanasia for histological and ultrastructural evaluation. The cumulative dose of DOX 150 mg/m2 over 15 weeks revealed significant effects on body weight, blood cells, functional enzymes, and cardiac injury biomarkers with alterations in electrocardiogram, myocardium, and renal tissue morphology. However, the dogs given CS-CaCO3NP-DOX 150 mg/m2 and below did not show any significant change in toxicity biomarker as compared to those given normal saline. The study confirmed the safety of repeated dose administration of CS-CaCO3NP-DOX (30 mg/m2) for 5 cycles in dogs. This finding offers opportunity to dogs with cancer that might require long-term administration of DOX without adverse effects.

Evaluation of in vitro efficacy of docetaxel-loaded calcium carbonate aragonite nanoparticles (DTX-CaCO3NP) on 4T1 mouse breast cancer cell line

Cockle shell-derived calcium carbonate nanoparticles have shown promising potentials as slow drug-releasing compounds in cancer chemotherapy. In this study, we evaluated the in vitro efficacy of docetaxel (DTX)-loaded CaCO₃NP on 4T1 cell line. This was achieved by evaluating the following: cytotoxicity using MTT assay, fluorescence imaging, apoptosis with Annexin V assay, cell cycle analysis, scanning (SEM) and transmission electron microscopy (TEM), and scratch assay. Based on the results, DTX-CaCO₃NP with a DTX concentration of 0.5 μg/mL and above had comparable cytotoxic effects with free DTX at 24 h, while all concentrations had similar cytotoxic effect on 4T1 cells at 48 and 72 h. Fluorescence and apoptosis assay showed a higher (p < 0.05) number of apoptotic cells in both free DTX and DTX-CaCO₃NP groups. Cell cycle analysis showed cycle arrest at subG0 and G2/M phases in both treatment groups. SEM showed presence of cellular blebbing, while TEM showed nuclear fragmentation, apoptosis, and vacuolation in the treatment groups. Scratch assay showed lower (p < 0.05) closure in both free DTX and DTX-CaCO₃NP groups. The results from this study showed that DTX-CaCO₃NP has similar anticancer effects on 4T1 cells as free DTX, and since it has a slow release rate, it is a more preferred substitute for free DTX.