Development and characterization dual responsive magnetic nanocomposites for targeted drug delivery systems

Fabrication and characterization of fish gelatin-based magnetic nanocomposite for biomedical applications

Bionanocomposite is considered an advanced way to bridge the gap between the structural and functional material and achieve the desired properties in the nanocomposite. This present study highlighted the synthesis of fish gelatin-based magnetic nanocomposite (GMNC) using three different concentrations of gelatin (6% w/v, G12% w/v, and 18% w/v) individually, through the in situ coprecipitation method. The effect of gelatin concentration on the structural, functional, magnetic properties, and biocompatibility of the GMNC was studied successfully. This variation reduces the crystallite size from 20.8 to 12.2 nm. GMNC obtained at minimum gelatin concentration (6% w/v) produced well-dispersed sphere-shaped magnetite nanoparticles with an average particle size of 33 nm without aggregation. All three reported superparamagnetic behavior at 293 K. It also noted the highly biocompatible and biodegradable nature of GMNC with a high magnetic response at a low magnetic field. This study reported the perspective of this functionalization method for biomedical applications, as GMNC is a potential carrier material that is easily attached to drug molecules through the free functional residues of gelatin molecules. The present study also performed the in vitro drug release behavior of 5'Fluorouracil-loaded GMNC (GF) at physiological conditions (pH 7.4 and 37 °C). It indicates the prepared GF exhibits a sustained drug-release profile for up to 48 h. Hence, these results strongly supported that the functionalized GMNC would be a potential carrier material for advanced drug delivery applications.

Thermo/pH dual-responsive micelles based on the host-guest interaction between benzimidazole-terminated graft copolymer and β-cyclodextrin-functionalized star block copolymer for smart drug delivery

Novel temperature and pH dual-sensitive amphiphilic micelles were fabricated exploiting the host-guest interaction between benzimidazole-terminated PHEMA-g-(PCL-BM) and β-CD-star-PMAA-b-PNIPAM. The fabricated graft copolymer had a brush-like structure with star side chains. The micelles were utilized as dual-responsive nanocarriers and showed the LCST between 40 and 41 °C. The acidic pH promoted the dissociation of the PHEMA-g-(PCL-BM: β-CD-star-PMAA-b-PNIPAM) micelles. DOX.HCl was loaded into the core of the micelles during self-assembly in an aqueous solution with a high encapsulation efficacy (97.3%). The average size of the amphiphilic micelles was about 80 nm, suitable size for the enhanced permeability and retention effect in tumor vasculature. In an aqueous environment, these micelles exhibited very good self-assembly ability, low CMC value, rapid pH- and thermo-responsiveness, optimal drug loading capacity, and effective release of the drug. The biocompatibility was confirmed by the viability assessment of human breast cancer cell line (MCF-7) through methyl tetrazolium assay. DOX-loaded micelles displayed excellent anti-cancer activity performance in comparison with free DOX.

Hypoxia-responsive block copolymer polyprodrugs for complementary photodynamic-chemotherapy

The inherent hypoxic microenvironment of solid tumors has an important influence on tumor growth, distant metastasis, and invasiveness. The heterogeneous distribution of hypoxic regions inside tumors limits the therapeutic efficacy of O₂-assisted therapeutic strategy (e.g. photodynamic therapy (PDT)). On the other hand, the hypoxia-activable prodrugs cannot work effectively in the regions with enough O₂ concentration. To address the issues, we prepare a block copolymer polyprodrug consisting of polyethylene glycol (PEG) and copolymerized segments of nitroimidazole-linked camptothecin (CPT) methacrylate and 5,10,15,20-tetraphenylporphyrin (TPP)-containing methacrylate monomers for complementary photodynamic-chemotherapy. The polyprodrug can self-assemble into polymeric micelles in aqueous solution with suitable size and high stability. After intravenous injection, the polyprodrug micelles show tumor accumulation. Followed by light irradiation (650 nm) at tumor sites, TPP moieties induce singlet oxygen (¹O₂) production in the oxygen-rich area to exert PDT and cause transformation of the oxygen-rich areas into hypoxia. Simultaneously, in the hypoxic areas, the hypoxia-responsive polyprodrugs can be activated to release free CPT due to the cleavage of nitroimidazole linkages. The polyprodrug micelles with the segments for PDT and hypoxia-activable CPT efficiently suppress the growth of HeLa tumors. The well-defined polyprodrug amphiphiles offer an effective strategy to overcome the disadvantages of single treatment of PDT or hypoxia-responsive prodrugs for complementary photodynamic-chemotherapy of cancers.

Carbohydrate-based magnetic nanocomposites for effective cancer treatment

The treatment of cancer includes several conventional therapies like surgery, radiation, chemotherapy, etc. but mostly associated with limitations like off-targeted action, fatigue and organ toxicity. The emergence of nanotechnology-enabled drug delivery systems shows revolutionary development to overcome the limitations of such therapies. Magnetic nanocomposites are the new area of research that consists of nanoscale magnetic materials for triggering the release of active in response to an external magnetic field. For targeted drug delivery and enhancing the biocompatibility, effective functionalization of magnetic nanocomposites is required. Therefore, several biological molecules like carbohydrate polymers, proteins, nucleic acids, antibodies, etc. are used. This review article focuses on the insights of advances in the development of carbohydrate-based magnetic nanocomposites for safe and effective cancer treatment. Carbohydrate-based magnetic nanocomposites offer significant advantages like greater stability, higher biocompatibility and lower toxicity with better physicochemical properties such as higher magnetic moments and anisotropy, larger heating properties, etc. Magnetic nanocomposites explore in almost all the areas of cancer therapeutics for drug delivery carrier, as antineoplastic and MRI contrast agents and in photothermal, photodynamic and in combinational therapies for the development of safer nanocarriers. Such progressive trend of carbohydrate-based magnetic nanocomposites will encourage the researchers for better site-specific delivery with higher safety profile in cancer therapy.

Chemotherapy of Breast Cancer Cells Using Novel pH-Responsive Cellulose-Based Nanocomposites

Purpose: The objective of the current study was to compare the anticancer efficacy of doxorubicin-loaded cellulose based magnetic (Fe3O4), zinc oxide (ZnO) nanoparticles on and free doxorubicin (DOX) on MCF-7 breast cancer cells. Methods: Novel pH-sensitive cellulose-graft poly acrylic acid based Fe3O4 (Cellulose-g-PAAg- PAcMNPs) and ZnO (Cellulose-g-PAA-g-PAcZnO) nanocomposites were synthesized via polymerization of acrylic acid and modified 3-(trimethoxysilyl) propyl methacrylate onto the cellulosic backbone via reversible addition-fragmentation chain transfer (RAFT) method. Results : Cellulose-g-PAA-g-PAcMNPs and Cellulose-g-PAA-g-PAcZnO nanocarriers with mean diameter of 15 and 38 nm were prepared successfully. DOX was loaded effectively to the ZnO and Fe3O4 nanocarriers via complexing and electrostatic force with great encapsulation efficiency of 99.07% and 98.92%, respectively. DOX-loaded nanocarriers showed obvious pHdependent tumor specific drug release pattern. MTT assay results indicated that IC50 of the DOX loaded Cellulose-g-PAA-g-PAcZnO, DOX loaded Cellulose-g-PAA-g-PAcMNPs and free DOX after 48 hours treatment with MCF7 cell lines were about 24.03, 49.27 and 99.76 μg mL-1, respectively. Therefore both DOX nanoformulations significantly increase antitumor ability compared to free DOX (P < 0.05). The results of MTT assay and DAPI staining revealed that DOX-loaded Cellulose-g-PAA-g-PAcZnO NPs show higher chemotherapy efficiency in MCF7 breast cancer cell line compare to the DOX-loaded Cellulose-g-PAA-g-PAcMNPs due to high interaction of ZnO with DOX. Conclusion: The formation of the complexes between the DOX and ZnO nanoparticles at the chelating sites of the quinone and the phenolic oxygen molecules of DOX, lead to more sustained drug release and enhanced chemotherapy effectiveness by increasing the intracellular concentration of DOX.

Poly-l-lysine-coated superparamagnetic nanoparticles: a novel method for the transfection of pro-BDNF into neural stem cells

Poly-l-lysine-coated superparamagnetic iron oxide nanoparticles (SPIONs-PLL) were prepared and used as a novel-carrier for the transfer of brain-derived neurotrophic factor (BDNF) into neural stem cells (NSCs) under the beneficial influence of an external magnetic field. Pro-BDNF, a gene from human brain cDNA libraries, was obtained by polymerase chain reaction and constructed in a mammalian expression vector (PSecTag2/HygroB). The nanoparticles (NPs) were examined using Fourier transform infrared spectroscopy, zeta potential, and Transmission electron microscopy. From the results, the levels of BDNF among the transfected and untransfected cells were 30.326 ± 5.9 and 5.85 ± 3.11 pg/mL, respectively, as detected by an ELISA method. Moreover, the enhanced green fluorescent protein vector was used to evaluate the gene expression efficiency for SPIONs-PLL as a non-viral carrier in NSCs. This was performed under the influence of a magnetic field and the transfection reagents (such as Lipofectamine 2000), which served as a positive control. The histological analysis revealed that the concentration of intracellular NPs was significantly higher than intercellular NPs. These results suggest that SPIONs-PLL can serve as a novel alternative for the transfection of BDNF-NSCs and could be used in gene therapy.

Theranostic nanoparticles based on magnetic nanoparticles: design, preparation, characterization, and evaluation as novel anticancer drug carrier and MRI contrast agent

In this work, we reported the synthesis of curcumin (CUR)-loaded hydrophilic and hydrophobic natural amino acids (AAs)-modified iron oxide magnetic nanoparticles (IONPs). Two types of AAs, l-lysine (Lys) and l-phenylalanine (PhA), were selected to study their effects on loading capacity, release profile of CUR, biocompatibility, and anticancer activity. CUR-loaded AAs-modified IONPs (F@AAs@CUR NPs) were characterized by X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FTIR), vibrating sample magnetometer (VSM), and transmission electron microscopy (TEM) techniques. Next, the various kinetic equations were fitted to the release data of CUR from F@Lys@CUR NPs and F@PhA@CUR NPs. Additionally, hemolysis test and MTT assays on HFF-2 and HEK-293 cell lines were performed for determination of biocompatibility of AAs-coated IONPs. Finally, the anticancer activity of F@AAs@CUR NPs examined on MCF-7 breast cancer cell line. The results indicate that these nanocarriers are nontoxic and biocompatible and also F@AAs@CUR NPs are suitable carriers for delivery of curcumin and even other hydrophobic drugs. Also, the MRI training established the effectiveness of IONPs as contrast agent for the revealing of tumor as evidenced from the phantom images as well as higher T₂ relaxivity.