Galactose-Containing Polymer-DOX Conjugates for Targeting Drug Delivery

Doxorubicin Conjugates: An Efficient Approach for Enhanced Therapeutic Efficacy with Reduced Side Effects

Continuous drug delivery modification is the scientific approach and is a basic need for the efficient therapeutic efficacy of active drug molecules. Polymer-drug conjugates have long been a hallmark of the drug delivery sector, with various conjugates on the market or in clinical trials. Improved drug solubilization, extended blood circulation, decreased immunogenicity, controlled release behavior, and increased safety are the advantages of conjugating drugs to the polymeric carrier like polyethylene glycol (PEG). Polymer therapies have evolved over the last decade, resulting in polymer-drug conjugates with diverse topologies and chemical properties. Traditional nondegradable polymeric carriers like PEG and hydroxy propyl methacrylate have been clinically employed to fabricate polymer-drug conjugates. Still, functionalized polymer-drug conjugates are increasingly being used to increase localized drug delivery and ease of removal. Researchers have developed multifunctional carriers that can "see and treat" patients using medicinal and diagnostic chemicals. This review focused on the various conjugation approaches for attaching the doxorubicin to different polymers to achieve enhanced therapeutic efficacy, that is, increased bioavailability and reduced adverse effects.

In vitro and in vivo evaluation of self-assembled chitosan nanoparticles selectively overcoming hepatocellular carcinoma via asialoglycoprotein receptor

Hepatocellular carcinoma (HCC) is one of the major causes of cancer-related mortality worldwide. Nowadays, liver-targeting drug delivery system has been proven as a promising strategy for overcoming HCC. Asialoglycoprotein receptor (ASGPR) is an ideal receptor for liver targeting, which is mainly expressed on hepatocytes. In this study, we developed several novel liver-targeting chitosan nanoparticles to selectively overcome HCC via ASGPR. Chitosan nanoparticles (Gly-CS-VE, Gal-Gly-CS-VE, Gly-CS-DCA, and Gal-Gly-CS-DCA) were prepared by grafting hydrophilic group (glycidol, Gly), hydrophobic group (deoxycholic acid, DCA or vitamin E succinate, VE), and ASGPR recognizing group (galactose, Gal). Subsequently, their characterizations were measured by ¹H NMR, FT-IR, TEM, and DLS. Doxorubicin (DOX) was loaded in nanoparticles and released out in a pH-dependent manner. Most importantly, the galactosylated Gal-Gly-CS-VE and Gal-Gly-CS-DCA nanoparticles exhibited significantly stronger in vitro cell internalization, cytotoxicity, anti-migration capabilities and in vivo anticancer efficacies than the corresponding Gly-CS-VE and Gly-CS-DCA nanoparticles, as well as free DOX. Finally, the four chitosan nanoparticles exhibited good biocompatibility without causing any obvious histological damage to the major organs. Overall, the galactosylated chitosan nanoparticles were proven to be promising pharmaceutical formulations for selectively overcoming HCC, with great potential for clinical applications.

Conventional and hybrid nanoparticulate systems for the treatment of hepatocellular carcinoma: An updated review

Hepatocellular carcinoma (HCC) is considered a serious malignancy which affects a large number of people worldwide. Despite the presence of some diagnostic techniques for HCC, the fact that its symptoms somehow overlap with other diseases causes it to be diagnosed at a late stage, hence negatively affecting the prognosis of the disease. The currently available treatment strategies have many shortcomings such as high cost, induction of serious side effects as well as multiple drug resistance, hence resulting in therapeutic failure. Accordingly, nanoformulations have been developed in order to overcome the clinical challenges, enhance the therapeutic efficacy, and elicit chemotherapy tailor-ability. Hybrid nanoparticulate carriers in particular, which are composed of two or more drug vehicles with different physicochemical characteristics combined together in one system, have been recently reported to advance nanotechnology-based therapies. Therefore, this review sheds the light on HCC, and the role of nanotechnology and hybrid nanoparticulate carriers as well as the latest developments in the use of conventional nanoparticles in combating this disease.

Glycosylated Nanoparticles for Cancer-Targeted Drug Delivery

Nanoparticles (NPs) are novel platforms that can carry both cancer-targeting molecules and drugs to avoid severe side effects due to nonspecific drug delivery in standard chemotherapy treatments. Cancer cells are characterized by abnormal membranes, metabolic changes, the presence of lectin receptors, glucose transporters (GLUT) overexpression, and glycosylation of immune receptors of programmed death on cell surfaces. These characteristics have led to the development of several strategies for cancer therapy, including a large number of carbohydrate-modified NPs, which have become desirable for use in cell-selective drug delivery systems because they increase nanoparticle-cell interactions and uptake of carried drugs. Currently, the potential of NP glycosylation to enhance the safety and efficacy of carried therapeutic antitumor agents has been widely acknowledged, and much information is accumulating in this field. This review seeks to highlight recent advances in NP stabilization, toxicity reduction, and pharmacokinetic improvement and the promising potential of NP glycosylation from the perspective of molecular mechanisms described for drug delivery systems for cancer therapy. From preclinical proof-of-concept to demonstration of therapeutic value in the clinic, the challenges and opportunities presented by glycosylated NPs, with a focus on their applicability in the development of nanodrugs, are discussed in this review.

pH-sensitive natural almond gum hydrocolloid based magnetic nanocomposites for theragnostic applications

In this study, iron oxide (γFe₂O₃) nanoparticles synthesized via hydrothermal route and doxorubicin (Dox) were successfully encapsulated into natural almond gum hydrocolloids via antisolvent precipitation technique. Cubic γFe₂O₃ crystal structure of the synthesized iron oxide nanoparticles were confirmed using X-ray diffraction and X-ray photoelectron spectroscopy. The refinement of XRD and elemental analysis revealed oxygen vacancies, which is also indicated by an increased magnetization comparable to bulk γFe₂O₃. Magnetization studies revealed the superparamagnetic nature of IO and IODPC nanoparticles. The particles were characterized for its morphology (TEM and FESEM), size (FESEM, DLS), surface charge (DLS) and MRI (proton relaxation). The heating ability of the IO and IODPC nanoparticles was studied and their specific absorption rate was found to be 83.06 W/g and 154.37 W/g respectively. The entrapment efficiency of the IODPC nanoparticles was found to be 88.29%. The drug release studies revealed that IODPC nanoparticles were more responsive towards acidic pH and their release follows Higuchi diffusion kinetics. In-vitro uptake and in-vitro cell viability studies were performed for IODPC nanoparticles using HeLA cell lines.

A Review on Targeting Nanoparticles for Breast Cancer

Chemotherapeutic agents have been used extensively in breast cancer remedy. However, most anticancer drugs cannot differentiate between cancer cells and normal cells, leading to toxic side effects. Also, the resulted drug resistance during chemotherapy reduces treatment efficacy. The development of targeted drug delivery offers great promise in breast cancer treatment both in clinical applications and in pharmaceutical research. Conjugation of nanocarriers with targeting ligands is an effective therapeutic strategy to treat cancer diseases. In this review, we focus on active targeting methods for breast cancer cells through the use of chemical ligands such as antibodies, peptides, aptamers, vitamins, hormones, and carbohydrates. Also, this review covers all information related to these targeting ligands, such as their subtypes, advantages, disadvantages, chemical modification methods with nanoparticles and recent published studies (from 2015 to present). We have discussed 28 different targeting methods utilized for targeted drug delivery to breast cancer cells with different nanocarriers delivering anticancer drugs to the tumors. These different targeting methods give researchers in the field of drug delivery all the information and techniques they need to develop modern drug delivery systems.

Doxorubicin-doxorubicin conjugate prodrug as drug self-delivery system for intracellular pH-triggered slow release

Drug content and releasing rate are the main determining factors for the drug delivery systems (DDSs). Here, doxorubicin dimer (D-DOXcar) was synthesized as drug-drug conjugate prodrug with high drug content of 86%, via an acid-triggered hydrolysable carbamate linker. The prodrug nanoparticles (D-DOXcar-NP) with different diameters were prepared as drug self-delivery system (DSDS) for intracellular pH-triggered slow release. They showed size- and concentration-dependent pH-triggered slow DOX release. For the D-DOXcar-sNP with smaller diameter, the cumulative release ratio reached 25.6% at pH 5.0 within 60 h. The MTT results demonstrated that the proposed DSDS showed similar tumor inhibition regardless of carboxylesterases, and an enhanced anti-tumor efficacy on the HepG2 cells in comparison with the free DOX.

Ionic Polymethacrylate Based Delivery Systems: Effect of Carrier Topology and Drug Loading

The presented drug delivery polymeric systems (DDS), i.e., conjugates and self-assemblies, based on grafted and star-shaped polymethacrylates have been studied for the last few years in our group. This minireview is focused on the relationship of polymer structure to drug conjugation/entrapment efficiency and release capability. Both graft and linear polymers containing trimethylammonium groups showed the ability to release the pharmaceutical anions by ionic exchange, but in aqueous solution they were also self-assembled into nanoparticles with encapsulated nonionic drugs. Star-shaped polymers functionalized with ionizable amine/carboxylic groups were investigated for drug conjugation via ketimine/amide linkers. However, only the conjugates of polybases were water-soluble, giving opportunity for release studies, whereas the self-assembling polyacidic stars were encapsulated with the model drugs. Depending on the type of drug loading in the polymer matrix, their release rates were ordered as follows: Physical ≥ ionic > covalent. The studies indicated that the well-defined ionic polymethacrylates, including poly(ionic liquid)s, are advantageous for designing macromolecular carriers due to the variety of structural parameters, which are efficient for tuning of drug loading and release behavior in respect to the specific drug interactions.