Anticancer nanodelivery system with controlled release property based on protocatechuate-zinc layered hydroxide nanohybrid

Green Synthesized Montmorillonite/Carrageenan/Fe3O4 Nanocomposites for pH-Responsive Release of Protocatechuic Acid and Its Anticancer Activity

Discovery of a novel anticancer drug delivery agent is important to replace conventional cancer therapies which are often accompanied by undesired side effects. This study demonstrated the synthesis of superparamagnetic magnetite nanocomposites (Fe₃O₄-NCs) using a green method. Montmorillonite (MMT) was used as matrix support, while Fe₃O₄ nanoparticles (NPs) and carrageenan (CR) were used as filler and stabilizer, respectively. The combination of these materials resulted in a novel nanocomposite (MMT/CR/Fe₃O₄-NCs). A series of characterization experiments was conducted. The purity of MMT/CR/Fe₃O₄-NCs was confirmed by X-ray diffraction (XRD) analysis. High resolution transmission electron microscopy (HRTEM) analysis revealed the uniform and spherical shape of Fe₃O₄ NPs with an average particle size of 9.3 ± 1.2 nm. Vibrating sample magnetometer (VSM) analysis showed an M_s value of 2.16 emu/g with negligible coercivity which confirmed the superparamagnetic properties. Protocatechuic acid (PCA) was loaded onto the MMT/CR/Fe₃O₄-NCs and a drug release study showed that 15% and 92% of PCA was released at pH 7.4 and 4.8, respectively. Cytotoxicity assays showed that both MMT/CR/Fe₃O₄-NCs and MMT/CR/Fe₃O₄-PCA effectively killed HCT116 which is a colorectal cancer cell line. Dose-dependent inhibition was seen and the killing was enhanced two-fold by the PCA-loaded NCs (IC₅₀–0.734 mg/mL) compared to the unloaded NCs (IC₅₀–1.5 mg/mL). This study highlights the potential use of MMT/CR/Fe₃O₄-NCs as a biologically active pH-responsive drug delivery agent. Further investigations are warranted to delineate the mechanism of cell entry and cancer cell killing as well as to improve the therapeutic potential of MMT/CR/Fe₃O₄-NCs.

Potential anticancer activity of protocatechuic acid loaded in montmorillonite/Fe3O4 nanocomposites stabilized by seaweed Kappaphycus alvarezii

Superparamagnetic magnetite nanocomposites (Fe₃O₄-NCs) were successfully synthesized, which comprised of montmorillonite (MMT) as matrix support, Kappaphycus alvarezii (SW) as bio-stabilizer and Fe₃O₄ as filler in the composites to form MMT/SW/Fe₃O₄-NCs. Nanocomposite with 0.5 g Fe₃O₄ (MMT/SW/0.5Fe₃O₄) was selected for anticancer activity study because it revealed high crystallinity, particle size of 7.2 ± 1.7 nm with majority of spherical shape, and M_s = 5.85 emu/g with negligible coercivity. Drug loading and release studies were carried out using protocatechuic acid (PCA) as the model for anticancer drug, which showed 19% and 87% of PCA release in pH 7.4 and 4.8, respectively. Monolayer anticancer assay showed that PCA-loaded MMT/SW/Fe₃O₄ (MMT/SW/Fe₃O₄-PCA) had selectivity towards HCT116 (colorectal cancer cell line). Although MMT/SW/Fe₃O₄-PCA (0.64 mg/mL) showed higher IC₅₀ than PCA (0.148 mg/mL) and MMT/SW/Fe₃O₄ (0.306 mg/mL, MMT/SW/Fe₃O₄-PCA showed more effective killing towards tumour spheroid model generated from HCT116. The IC₅₀ for MMT/SW/Fe₃O₄-PCA, MMT/SW/Fe₃O₄ and PCA were 0.132, 0.23 and 0.55 mg/mL, respectively. This suggests the improved penetration efficiency and drug release of MMT/SW/Fe₃O₄-PCA towards HCT116 spheroids. Moreover, concentration that lower than 2 mg/mL MMT/SW/Fe₃O₄-PCA did not result any hemolysis in human blood, which suggests them to be ideal for intravenous injection. This study highlights the potential of MMT/SW/Fe₃O₄-NCs as drug delivery agent.

Sustained release of anticancer agent phytic acid from its chitosan-coated magnetic nanoparticles for drug-delivery system

Chitosan (CS) iron oxide magnetic nanoparticles (MNPs) were coated with phytic acid (PTA) to form phytic acid-chitosan-iron oxide nanocomposite (PTA-CS-MNP). The obtained nanocomposite and nanocarrier were characterized by powder X-ray diffraction, Fourier transform infrared spectroscopy, vibrating sample magnetometry, transmission electron microscopy, and thermogravimetric and differential thermogravimetric analyses. Fourier transform infrared spectra and thermal analysis of MNPs and PTA-CS-MNP nanocomposite confirmed the binding of CS on the surface of MNPs and the loading of PTA in the PTA-CS-MNP nanocomposite. The coating process enhanced the thermal stability of the anticancer nanocomposite obtained. X-ray diffraction results showed that the MNPs and PTA-CS-MNP nanocomposite are pure magnetite. Drug loading was estimated using ultraviolet-visible spectroscopy and showing a 12.9% in the designed nanocomposite. Magnetization curves demonstrated that the synthesized MNPs and nanocomposite were superparamagnetic with saturation magnetizations of 53.25 emu/g and 42.15 emu/g, respectively. The release study showed that around 86% and 93% of PTA from PTA-CS-MNP nanocomposite could be released within 127 and 56 hours by a phosphate buffer solution at pH 7.4 and 4.8, respectively, in a sustained manner and governed by pseudo-second order kinetic model. The cytotoxicity of the compounds on HT-29 colon cancer cells was evaluated by 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide assay. The HT-29 cell line was more sensitive against PTA-CS-MNP nanocomposite than PTA alone. No cytotoxic effect was observed on normal cells (3T3 fibroblast cells). This result indicates that PTA-CS-MNP nanocomposite can inhibit the proliferation of colon cancer cells without causing any harm to normal cell.

Graphene oxide as a nanocarrier for controlled release and targeted delivery of an anticancer active agent, chlorogenic acid

We have synthesized graphene oxide using improved Hummer's method in order to explore the potential use of the resulting graphene oxide as a nanocarrier for an active anticancer agent, chlorogenic acid (CA). The synthesized graphene oxide and chlorogenic acid-graphene oxide nanocomposite (CAGO) were characterized using Fourier transform infrared (FTIR) spectroscopy, thermogravimetry and differential thermogravimetry analysis, Raman spectroscopy, powder X-ray diffraction (PXRD), UV-vis spectroscopy and high resolution transmission electron microscopy (HRTEM) techniques. The successful conjugation of chlorogenic acid onto graphene oxide through hydrogen bonding and π-π interaction was confirmed by Raman spectroscopy, FTIR analysis and X-ray diffraction patterns. The loading of CA in the nanohybrid was estimated to be around 13.1% by UV-vis spectroscopy. The release profiles showed favourable, sustained and pH-dependent release of CA from CAGO nanocomposite and conformed well to the pseudo-second order kinetic model. Furthermore, the designed anticancer nanohybrid was thermally more stable than its counterpart. The in vitro cytotoxicity results revealed insignificant toxicity effect towards normal cell line, with a viability of >80% even at higher concentration of 50μg/mL. Contrarily, CAGO nanocomposite revealed enhanced toxic effect towards evaluated cancer cell lines (HepG2 human liver hepatocellular carcinoma cell line, A549 human lung adenocarcinoma epithelial cell line, and HeLa human cervical cancer cell line) compared to its free form.

Graphene Oxide-Gallic Acid Nanodelivery System for Cancer Therapy

Despite the technological advancement in the biomedical science, cancer remains a life-threatening disease. In this study, we designed an anticancer nanodelivery system using graphene oxide (GO) as nanocarrier for an active anticancer agent gallic acid (GA). The successful formation nanocomposite (GOGA) was characterized using XRD, FTIR, HRTEM, Raman, and UV/Vis spectroscopy. The release study shows that the release of GA from the designed anticancer nanocomposite (GOGA) occurs in a sustained manner in phosphate-buffered saline (PBS) solution at pH 7.4. In in vitro biological studies, normal fibroblast (3T3) and liver cancer cells (HepG2) were treated with different concentrations of GO, GOGA, and GA for 72 h. The GOGA nanocomposite showed the inhibitory effect to cancer cell growth without affecting normal cell growth. The results of this research are highly encouraging to go further for in vivo studies.

Unique antitumor property of the Mg-Ca-Sr alloys with addition of Zn

In clinical practice, tumor recurrence and metastasis after orthopedic prosthesis implantation is an intensely troublesome matter. Therefore, to develop implant materials with antitumor property is extremely necessary and meaningful. Magnesium (Mg) alloys possess superb biocompatibility, mechanical property and biodegradability in orthopedic applications. However, whether they possess antitumor property had seldom been reported. In recent years, it showed that zinc (Zn) not only promote the osteogenic activity but also exhibit good antitumor property. In our present study, Zn was selected as an alloying element for the Mg-1Ca-0.5Sr alloy to develop a multifunctional material with antitumor property. We investigated the influence of the Mg-1Ca-0.5Sr-xZn (x = 0, 2, 4, 6 wt%) alloys extracts on the proliferation rate, cell apoptosis, migration and invasion of the U2OS cell line. Our results show that Zn containing Mg alloys extracts inhibit the cell proliferation by alteration the cell cycle and inducing cell apoptosis via the activation of the mitochondria pathway. The cell migration and invasion property were also suppressed by the activation of MAPK (mitogen-activated protein kinase) pathway. Our work suggests that the Mg-1Ca-0.5Sr-6Zn alloy is expected to be a promising orthopedic implant in osteosarcoma limb-salvage surgery for avoiding tumor recurrence and metastasis.

Synthesis, controlled release and antibacterial studies of nalidixic acid–zinc hydroxide nitrate nanocomposites

Nalidixic acid intercalated zinc hydroxide nitrate is suitable for a controlled-release formulation and the resultant nanocomposite is an effective antibacterial agent.

New biocompatible hydroxy double salts and their drug delivery properties

Two novel biocompatible hydroxy double salts (HDSs) have been synthesised, loaded with the drug naproxen, and formulated into tablets.

Impact of size, secondary structure, and counterions on the binding of small ribonucleic acids to layered double hydroxide nanoparticles

Use of ribonucleic acid (RNA) interference to regulate protein expression has become an important research topic and gene therapy tool, and therefore, finding suitable vehicles for delivery of small RNAs into cells is of crucial importance. Layered double metal hydroxides such as hydrotalcite (HT) have shown great promise as nonviral vectors for transport of deoxyribose nucleic acid (DNA), proteins, and drugs into cells, but the adsorption of RNAs to these materials has been little explored. In this study, the binding of small RNAs with different lengths and levels of secondary structure to HT nanoparticles has been analyzed and compared to results obtained with small DNAs in concurrent experiments. Initial experiments established the spectrophotometric properties of HT in aqueous solutions and determined that HT particles could be readily sedimented with near 100% efficiencies. Use of RNA+HT cosedimentation experiments as well as electrophoretic mobility shift assays demonstrated strong adsorption of RNA 25mers to HT, with twofold greater binding of single-stranded RNAs relative to double-stranded molecules. Strong affinities were also observed with ssRNA and dsRNA 54mers and with more complex transfer RNA molecules. Competition binding and RNA displacement experiments indicated that RNA-HT associations were strong and were only modestly affected by the presence of high concentrations of inorganic anions.

Release behaviour and toxicity evaluation of levodopa from carboxylated single-walled carbon nanotubes

This work explores the potential use of commercially obtained, carboxylated, single-walled carbon nanotubes (SWCNT-COOH) as nanocarriers for the antiparkinson drug, levodopa (LD). The resulting nanohybrid was characterized using materials characterization methods including Fourier transform infrared spectroscopy, Raman spectroscopy, elemental analysis, UV-vis spectroscopy and scanning electron microscopy. The results showed that SWCNT-COOH were able to form supramolecular complexes with LD via a π-π stacking interaction and exhibited favourable, slow, sustained-release characteristics as a drug carrier with a release period over more than 20 h. The results obtained from the drug release studies of LD at different pH values showed that the LD-loaded nanohybrid is pH activated. The release kinetics of LD from SWCNT-COOH were well-described by a pseudo-second-order kinetic model. A cytotoxicity assay of the synthesized nanohybrid was also carried out in PC12 cell lines (a widely used, in vitro Parkinson's model for neurotoxicity studies) using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay in order to investigate their possible effects on normal neuronal cells in vitro. It was found that the synthesized nanohybrid did not compromise the cell viability and the PC12 cells remained stable throughout the experiments up to 72 h after treatment.