Magnetic ferrite nanoparticles coated with bovine serum albumin and glycine polymers for controlled release of curcumin as a model

To conquer the low water solubility and bioavailability of curcumin (CUR), to corroborate its functional qualities and to broaden its applicability in the pharmaceutical sector, numerous nanoscale methods have been widely exploited for its administration. Because of its polycystic, biodegradable, biocompatibility, non-toxicity, and non-allergenic properties, bovine serum albumin (BSA) and glycine (Gly) have been actively investigated as natural biopolymers for decades. Various BSA and Gly-based nanocarriers with unique features for CUR delivery, such as magnetic ferrite nanoparticles, are being developed (MNPs). In this work, magnesium ferrite (MgFe2O4)/BSA and nickel ferrite (NiFe2O4)/Gly nanocomposites loaded with CUR (drug model) were manufactured for the first time using a chemical co-precipitation approach to create biocompatible drug nanocarriers. It was found that the synthesized MgFe2O4/BSA and NiFe2O4/Gly nanoparticles have a uniform particle distribution and their size is much less than 100 nm. Saturation magnetization in MgFe2O4 and NiFe2O4 reaches 13.07 and 33.4 emu/g the remarkable peak of magnetization decreases to 10.99 and 32.36 emu/g after the addition of polymers. These analyses also showed the presence of chemical bonds in the structure of the nanocomposite. The curcumin diffusion process in NPs were determined using a mathematical modeling. The yielding of the product for MgFe2O4/BSA and NiFe2O4/Gly in 200 h is about 72 and 63%, respectively. Also, regressed relative diffusivities (D/R2), including effective steric hindrance, were determined as 5.75 × 10-4 and 2.72 × 10-4 h-1 for MgFe2O4/BSA and NiFe2O4/Gly, respectively. It shows that there is a significant steric barrier that significantly deviates from the molecular diffusion of the liquid. As a result, the low effective release of curcumin in the particles is more noticeable. Our study demonstrated the effective relationship between the polymer architecture and the biophysical properties of the resulting nanoparticles and shed light on new approaches for the design of efficient NP-based drug carriers.

DOX-loaded hydroxyapatite nanoclusters for colorectal cancer (CRC) chemotherapy: Evaluation based on the cancer cells and organoids

It is meaningful to find suitable in vitro models for preclinical toxicology and efficacy evaluation of nanodrugs and nanocarriers or drug screening and promoting clinical transformation of nanocarriers. The emergence and development of organoids technology provide a great possibility to achieve this goal. Herein, we constructed an in vitro 3D organoid model to study the inhibitory effect of nanocarriers on colorectal cancer. And designed hydroxyapatite nanoclusters (c-HAP) mediated by polydopamine (PDA) formed under alkaline conditions (pH 9.0), then used c-HAP to load DOX (c-HAP/DOX) as nanocarrier for improved chemotherapy. In vitro, drug release experiments show that c-HAP/DOX has suitable responsive to pH, can be triggered to the facile release of DOX in a slightly acidic environment (pH 6.0), and maintain specific stability in a neutral pH value (7.4) environment. c-HAP/DOX showed an excellent antitumor effect in the two-dimensional (2D) cell model and three-dimensional (3D) patient-derived colon cancer organoids (PDCCOs) model. In addition, c-HAP/DOX can release a sufficient amount of DOX to produce cytotoxicity in a slightly acidic environment, entering efficiently into the colorectal cancer cells caused endocytosis and induced apoptosis. Therefore, organoids can serve as an effective in vitro model to present the structure and function of colorectal cancer tissues and be used to evaluate the efficacy of nanocarriers for tumors.

A doxorubicin-platinum conjugate system: impacts on PI3K/AKT actuation and apoptosis in breast cancer cells

In recent years, the development of a nano-conjugate system for drug delivery applications has gained attention among researchers. Keeping this in mind, in this study, we developed a doxorubicin-platinum conjugate system that targeted breast cancer cell lines. To achieve this, we developed platinum nanoparticles using polyvinylpyrrolidone (PVP). High resolution-transmission electron microscopy (HR-TEM) revealed the occurrence of octopod-shaped platinum nanoparticles. Subsequently, doxorubicin (DOX) was conjugated on the surface of the as-prepared platinum octopods via an in situ stirring method. The physicochemical characterization of the doxorubicin-platinum conjugate system revealed that the PVP of PtNPs interacts with the NH2 group of doxorubicin via electrostatic interaction/hydrogen bonding. Besides, the doxorubicin-platinum conjugate system exhibited a sustained drug release profile within the cancer cells. Furthermore, the evaluation of the in vitro anticancer efficacy of the doxorubicin-platinum conjugate system in breast cancer cells (MCF-7 and MDA-MB-231) unveiled the induction of apoptosis via intracellular ROS and DNA damage, rather than free DOX and PtNPs. Remarkably, we also perceived that the doxorubicin-platinum conjugate system was strong enough to down-regulate the PI3K/AKT signalling pathway. As a result, the tumour suppressor gene PTEN was activated, which led to the stimulation of a mitochondrion-based intrinsic apoptotic pathway and its downstream caspases, triggering cell death. Hence, our findings suggested that a biologically stable doxorubicin-platinum conjugate system could be an imperative therapeutic agent for anticancer therapy in the near future.

A novel multifunctional NCQDs-based injectable self-crosslinking and in situ forming hydrogel as an innovative stimuli responsive smart drug delivery system for cancer therapy

In this work, we offer an easy approach to develop a novel injectable, pH sensitive and in situ smart drug delivery system for use in cancer treatments. The developed hydrogels containing nitrogen doped carbon quantum dots (NCQD), doxorubicin (Dox) and hydroxyapatite (HA) were obtained by in situ self-crosslinking. Characterization of the synthesized nanomaterials, interactions between NCQD/Dox/HA hydrogel structure were carried out by TEM, FESEM, EDS, FTIR, XPS, XRD, Zeta potential, DLS, UV-Vis, SEM, gelation time, injectability and DIST measurements. In addition, antibacterial evaluation which was performed against Staphylococcus aureus realized that HA compound significantly increased the antibacterial activity of the hybrid hydrogel. The anticancer drug release to the tumor cell microenvironment with a pH of 5.5 was found to be higher compared to the release in the normal physiological range of pH 6.5 and 7.4. MTT and live/dead assays were also performed using L929 fibroblastic cell lines to investigate the cytotoxic behavior of NCQDs, and NCQDs/Dox/HA hydrogels. Furthermore, the NCQDs/Dox/HA hydrogel could transport Dox within a MCF-7 cancerous cell at specifically acidic pH. Additionally, imaging of cell line was observed using NCQDs and their use in imaging applications and multicolor features in the living cell system were evaluated. The overall study showed that in situ formed NCQDs/Dox/HA hydrogel represented a novel and multifunctional smart injectable controlled-release drug delivery system with great potential, which may be considered as an attractive minimal invasive smart material for future intelligent delivery of chemotherapeutic drug and disease therapy applications.

Targeting self-assembled F127-peptide polymer with pH sensitivity for release of anticancer drugs

The treatment of breast cancer mainly relies on chemotherapy drugs, which present significant side effects.

Aldehyde-Functionalized Magnetic Particles to Capture Off-Target Chemotherapeutic Agents

Drug capture is a promising technique to prevent off-target chemotherapeutic agents from reaching systemic circulation and causing severe side effects. The current work examines the viability of using immobilized aldehydes for drug-capture applications via Schiff base formation between doxorubicin (DOX) and aldehydes. Commercially available pyridoxal-5'-phosphate (VB6) was immobilized on iron oxide nanoparticles (IONPs) to capture DOX from human serum. Leaching of VB6 persisted as a primary issue and thus various aldehydes with anchoring groups such as catechol, silatrane, and phosphonate esters have been studied. The phosphonate group-based anchor was the most stable and used for further capture studies. To improve the hydrophilic nature of the aldehydes, sulfonate-containing aldehydes and polyethylene glycols (PEGs) were investigated. Finally, the optimized functionalized iron oxide particles, PEGylated-IONP, were used to demonstrate doxorubicin capture from human serum at biologically relevant temperature (37 °C), time (30 min), and concentrations (μM). The current study sets the stage for the development of potential compact dimension capture device based on surface-anchorable polymers with aldehyde groups.

Taurine-Conjugated Mussel-Inspired Iron Oxide Nanoparticles with an Elongated Shape for Effective Delivery of Doxorubicin into the Tumor Cells

Multifunctional iron oxide magnetic nanoparticles, among them nanorods, were prepared with a mussel-inspired polydopamine (pDA) surface coating agent for cancer therapeutics. Taurine, a free sulfur-containing ß amino acid, was grafted on the pDA at the iron oxide nanoparticle surface to enhance its biocompatibility and targeted delivery action. Doxorubicin (DOX), an anticancer drug, was loaded on the prepared nanovehicles with an entrapment efficiency of 70.1%. Drug release kinetics were then analyzed using UV-vis and fluorescence spectroscopies, suggesting the pH-responsive behavior of the developed nanovehicle. The developed system was then tested on PC-3 cell lines to check its cellular response. Confocal microscopy observations and (3-(4,5-dimethylthiazol-2-yl)-5-(3-carboxymethoxyphenyl)-2-(4-sulfophenyl)-2H-tetrazolium) and Annexin V-FITC assays used to evaluate cell toxicity and apoptosis reveal a dose-dependent nature of nanorods and can overcome the side effects of using free DOX with a targeted action.

Glutamic acid-coated Fe3O4 nanoparticles for tumor-targeted imaging and therapeutics

We have developed surface functionalised Fe₃O₄ magnetic nanoparticles (MNPs) based system that can be used for tumor-targeted multimodal therapies and MR imaging. Biocompatible, non-essential amino acid (glutamic acid) was introduced onto the surface of Fe₃O₄ MNPs to provide functional sites for binding of chemotherapeutic drugs. These glutamic acid-coated Fe₃O₄ MNPs (GAMNPs) exhibit good water-dispersibility, magnetic responsivity and pH dependent charge conversal feature. The magnetic core as well as organic shell of GAMNPs was characterized by XRD, TEM, DLS, FTIR, PPMS and UV-visible spectroscopy and zeta-potential analyzer etc. The broad spectrum anticancer drugs, doxorubicin hydrochloride (DOX) and methotrexate (MTX) were electrostatically and covalently conjugated to the surface of GAMNPs, respectively for combination chemotherapy. These dual drugs loaded system (DOX-MTX-GAMNPs) shows pH dependent release behaviour of both the drugs and enhanced toxicity towards breast cancer cell line (MCF-7) as compared to their individual treatment. Fluorescence microscopy and flow cytometric analyses confirmed the successful uptake of drug loaded system into MCF-7 cell lines. Further MTX being analogue of folic acid, its co-delivery with DOX would help in internalization of both the drugs into MCF-7 cells. These GAMNPs also show good heating efficiency under AC magnetic field (Intrinsic loss power, ILP = 0.95 and 0.73 and 0.48 nHm²/Kg at Fe concentration of 0.5, 1 and 2 mg/ml, respectively) and transverse relaxivity (r₂ = 152 mM^-1 s^-1) indicating their potential capability for hyperthermia therapy and MRI tracking. Furthermore, it has been observed that the combination of chemotherapeutic drugs and hyperthermia leads to an enhancement of cytotoxicity in MCF-7 cells.

Synthetic routes to nanoconjugates of anthracyclines

Anthracyclines (Anth) are widely used in the treatment of various types of cancer. Unfortunately, they exhibit serious adverse effects, such as hematopoietic depression and cardiotoxicity, leading to heart failure. In this review, we focus on recently developed conjugates of anthracyclines with a range of nanocarriers, such as polymers, peptides, DNA or inorganic systems. Manipulation of the composition, size and shape of chemical entities at the nanometer scale makes possible the design and development of a range of prodrugs. In this review we concentrate on synthetic chemistry in the long process leading to the introduction of novel therapeutic products.

A pH-sensitive carrier based-on modified hollow mesoporous carbon nanospheres with calcium-latched gate for drug delivery

A novel nanocarrier based-on hollow mesoporous carbon nanospheres (HMCNs) with primary amines on its surface, a large cavity, and good hydrophilicity was synthesized by a hydrothermal reaction. The primary amine functionalities on the mesoporous carbon were used as the initiation sites for growing poly (epichlorohydrin) (PCH) chains. The chlorine groups in the side chain of PCH were replaced with imidazole as the pendant groups. Calcium chloride (CaCl₂) was applied as a capping agent. The coordination bonding was formed between pendant imidazole groups and calcium ions. Doxorubicin (DOX) was selected as a model of hydrophilic anticancer drug and was loaded onto the nanocarrier and released through the cleavage of the pH-sensitive coordination bonding. The gating mechanism enables the nanocarrier to store and release the calcium ions and the DOX molecules trapped in the pores. MTT assay toward HeLa cells indicated that the nanocarrier had low toxicity because of the surface modification with the oxygen-rich polymer. The cellular uptake of the pH-sensitive nanocarrier for HeLa cancer cell lines was confirmed by CLSM images and flow cytometry. So, the novel pH-sensitive nanocarrier can be applicable to carry and release both DOX drug and calcium ions for cancer treatment.

Functionalized calcium orthophosphates (CaPO4) and their biomedical applications

Due to the chemical similarity to natural calcified tissues (bones and teeth) of mammals, calcium orthophosphates (abbreviated as CaPO₄) appear to be good biomaterials for creation of artificial bone grafts. However, CaPO₄ alone have some restrictions, which limit their biomedical applications. Various ways have been developed to improve the properties of CaPO₄ and their functionalization is one of them. Namely, since surfaces always form the interfaces between implanted grafts and surrounding tissues, the state of CaPO₄ surfaces plays a crucial role in the survival of bone grafts. Although the biomedically relevant CaPO₄ possess the required biocompatible properties, some of their properties could be better. For example, functionalization of CaPO₄ to enhance cell attachment and cell material interactions has been developed. In addition, to prepare stable formulations from nanodimensional CaPO₄ particles and prevent them from agglomerating, the surfaces of CaPO₄ particles are often functionalized by sorption of special chemicals. Furthermore, there are functionalizations in which CaPO₄ are exposed to various types of physical treatments. This review summarizes the available knowledge on CaPO₄ functionalizations and their biomedical applications.

Directly covalent immobilization of Candida antarctica lipase B on oxidized aspen powder by introducing poly‑lysines: An economical approach to improve enzyme performance

In our previous study, we could achieve high soluble expression of Candida antarctica lipase B (CalB) in E. coli by fusion poly‑amino acid tags on CalB (pCalB). Herein, we are surprised to find that pCalB can be easily and directly covalent binding on a simply oxidized aspen powder (OAP) by the aid of poly‑lysine tags. Under the optimal conditions, 72.9 ± 3.6% of the total protein could be immobilized, and the activity recovery of immobilized pCalB (pCalB-OAP) was 98.9 ± 3.8%. The analysis of scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) indicated that OAP was a suitable carrier for enzyme immobilization. The immobilized pCalB-OAP could exhibit excellent thermal stabilities, and it retained a residual activity of 58.4 ± 2.8% at 55 °C, whereas only 21.2 ± 2.2% of its initial activity for free pCalB was observed. And it could also display a nice tolerance for the changes of pH environment, compared with that of free pCalB. The results that pCalB-OAP could retained 73.6 ± 2.9% of their initial activity in (R, S)-NEMPAME hydrolysis after the tenth cycles, suggested that pCalB-OAP could be effectively recycled. The immobilization strategies established here were simple and inexpensive.

A novel smart PEGylated gelatin nanoparticle for co-delivery of doxorubicin and betanin: A strategy for enhancing the therapeutic efficacy of chemotherapy

Betanin (BET) can reduce the side effects of potent anticancer drugs e.g. doxorubicin (DOX) on the normal tissues in co-administration with them because of the synergistic therapeutic effect and consequently the reduced required amount of anticancer agents. Despite interest in the use of BET, incomplete oral absorption and low stability of BET limit its application. Thus, in this study to overcome the restrictions of BET and providing the synergistic effect of DOX@BET, we designed a new pH-responsive nanocarrier via decoration of gelatin nanoparticles (GNPs) by (methoxy poly (ethylene glycol)-poly ((2-dimethylamino) ethyl methacrylate-co-itaconic acid) (PGNPs). DOX and BET were effectively loaded (the loading capacity of 20.5% and 16.25%, respectively) into the PGNPs and this nanoplatform exhibited the suitable small particle size (162 nm). Additionally, the triggered release ability of drugs was studied through the assessment of simulated physiological and tumor tissue environments and showed the controlled release of DOX and BET with adjusting the pH of environment. Moreover, the synergistic effect of DOX@BET loaded PGNPs decreased the cell viability amount of breast cancer cells (MCF-7) respect to the free form of DOX or BET which indicated that the developed smart nanocarrier will be a hopeful nanocarrier for cancer therapy.

Facile covalent bio-conjugation of hydroxyapatite

A facile covalent bio-conjugation of hydroxyapatite has been developed and employed for the conjugation of hydrophobic proteins.