Comb-like PEG-containing polymeric composition as low toxic drug nanocarrier

Tunable Cell-Adhesive Surfaces by Surface-Initiated Photoinduced Electron-Transfer-Reversible Addition-Fragmentation Chain-Transfer Polymerization

Cell adhesion involves many interactions between various molecules on the cell membrane (receptors, coreceptors, integrins, etc.) and surfaces or other cells. Cell adhesion plays a crucial role in the analysis of immune response, cancer treatment, tissue engineering, etc. Cell-cell adhesion can be quantified by measuring cell avidity, which defines the total interaction strength of the live cell binding. Typically, those investigations use tailor-made, reusable chips or surfaces onto which cells are cultured to form a monolayer to which other cells can bind. Cell avidity can then be measured by applying a force and quantifying cell-cell bond ruptures. The subsequent cleaning and reactivation of such biochip and biointeractive surfaces often require repeated etching, leading to device damage. Furthermore, it is often of great interest to harvest the cells that remain bound at the end of an avidity experiment for further analysis or use. It is, therefore, advantageous to pursue coating methods that allow tunable cell adhesion. This work presents temperature-switchable poly(di(ethylene glycol) methyl ether methacrylate) brush-based cell-interactive coatings produced by surface-initiated photoinduced electron-transfer reversible addition-fragmentation chain-transfer polymerization. The temperature switch of these brushes was explored by using a quartz crystal microbalance with dissipation monitoring, chemical composition, and physicochemical properties by atom force microscopy, X-ray photoelectron spectroscopy, single-molecule force spectroscopy, and ellipsometry.

CES1-Triggered Liver-Specific Cargo Release of CRISPR/Cas9 Elements by Cationic Triadic Copolymeric Nanoparticles Targeting Gene Editing of PCSK9 for Hyperlipidemia Amelioration

The broad application of clustered regularly interspaced short palindromic repeat (CRISPR)/Cas9 genome editing tools is hindered by challenges in the efficient delivery of its two components into specific cells and intracytoplasmic release. Herein, a novel copolymer for delivery of Cas9-mRNA/ single-guide RNA (Cas9-mRNA/sgRNA) in vitro and vivo, using carboxylesterase-responsive cationic triadic copolymeric nanoparticles targeted proprotein convertase subtilisin/kexin type 9 (PCSK9) for hyperlipidemia amelioration is reported. A dimethyl biguanide derivative is designed and synthesized to form cationic block, and copolymerization onto prepolymer with propyl methacrylate, to fabricate a triadic copolymer mPEG-b-P(Met/n-PMA). The copolymer can self-assemble with Cas9-mRNA/sgRNA, indicating the excellent potential of nanoparticles to form a delivery carrier. This vehicle can efficiently release RNA in response to the hepatocytes carboxylesterase for genome editing. It was demonstrated that the mPEG-b-P(Met/n-PMA)/Cas9 mRNA/sgRNA nanoparticles effectively accumulated in hepatocytes, lead to the inhibition of PCSK9, and lowered the levels of Low-density lipoprotein cholesterol and total cholesterol in mouse serum down 20% of nontreatment. Interestingly, the nanoparticles even enable multiple functions in the regulation of blood glucose and weight. This study establishes a novel method to achieve complex CRISPR components stable loading, safe delivery, and fixed-point release, which expand the application of CRISPR delivery systems.

Covalent Conjugate of Ser-Pro-Cys Tripeptide with PEGylated Comb-Like Polymer as Novel Killer of Human Tumor Cells

Recently, we detected a previously unknown Ser-Pro-Cys (SPC) tripeptide in the blood serum of multiple sclerosis patients. Its role as a biomarker of the autoimmune disease was suggested, although its origin and real biological activity remained unclear. Here, we created a biocompatible PEGylated comb-like polymer that was used as a platform for covalent immobilization of the SPC, which provided a possibility to explore the biological activity of this tripeptide. This macromolecular conjugate was synthesized via a reaction of the terminal epoxide group of the biocompatible copolymer of dimethyl maleate (DMM) and polyethylene glycol methyl ether methacrylate (PEGMA) with the amino group of the SPC tripeptide. Unexpectedly, the resulting conjugate containing SPC demonstrated anticancer activity in vitro. It possessed pro-apoptotic action toward human tumor cells, while there was no cytotoxic effect of that conjugate toward normal lymphocytes of human peripheral blood. The detected biological effects of the created conjugate inspired us to carry out a thorough study of structural and colloidal-chemical characteristics of this surface-active copolymer containing side PEG chains and a terminal nontoxic synthetic fragment. The copolymer composition, in particular, the content of the peptide fragment, was determined via elemental analysis and NMR spectroscopy. At CMC, it formed polymeric micelle-like structures with a hydrodynamic diameter of 180 ± 60 nm. The conjugation of the peptide fragment to the initial comb-like copolymer caused a change of zeta-potential of the formed micelle-like structures from -0.15 to 0.32 mV. Additional structural modification of the created polymeric nanoplatform was performed via attachment of fluorescein isothiocianate (FITC) dye that permitted monitoring of the behavior of the bioactive SPC-functionalized conjugate in the treated tumor cells. Its penetration into those cells and localization in their cytoplasm were revealed. The principal novelty of this study consists in finding that covalent conjugation of two nontoxic compounds-SPC tripeptide and comb-like PEGylated polymer-led to an unexpected synergy which appeared in the distinct cytotoxic action of the macromolecular complex toward human tumor cells. A potential role of peculiarities of the colloidal-chemical properties of the novel conjugate in its cytotoxic effect are discussed. Thus, synthesized comb-like PEGylated polymers can provide a prospective nanoplatform for drug delivery in anticancer chemotherapy.

Pegylated Curcumin Derivative: Water-Soluble Conjugates with Antitumor and Antibacterial Activity

During the past years, the synthesis of polymer prodrug structures, based on natural phytochemical compounds with a great range of valuable biological properties, has become a promising solution in cancer prevention, imaging, and detection. Curcumin (Curc) remains one of the most studied natural products, due to the impressive palette of biological properties and the possibility to be easily loaded in various micro- and nanostructures and chemically modified. In this study, pegylated curcumin derivatives were prepared by a direct esterification reaction between poly(ethylene glycol)diacid (PEG of 600 g/mol molar mass, PEG₆₀₀) and Curc in the presence of N,N'-dicyclohexylcarbodiimide (PEG₆₀₀-Curc). The successful reaction resulted in a water-soluble stable product that was characterized by infrared spectroscopy (Fourier transform infrared (FT-IR)) and proton (¹H) and carbon (¹³C) NMR. The effect of the pH values of buffer solutions on PEG₆₀₀-Curc spectral properties (absorption and photoluminescence) was investigated by UV-vis and fluorescence spectrophotometry. Based on the biological tests, it was confirmed that PEG₆₀₀-Curc exhibits cytotoxic activity against Graffi cell lines, as a function of the Curc concentration in the conjugate and the incubation time. PEG₆₀₀-Curc antibacterial activity was validated in microbiological tests against pathogenic microorganisms such as Staphylococcus aureus. Most importantly, despite the covalent attachment of Curc to PEG and the slight reduction in the therapeutic index of the conjugate, both the anticancer and antimicrobial activities remain the highest reported, thus opening the gate for further, more clinically oriented studies.

Nose-to-brain drug delivery for the treatment of Alzheimer's Disease: Current advancements and challenges

INTRODUCTION

The irreversible destruction of neurons, progressive loss of memory and cognitive behavior, high cost of therapy, and impact on society desire a better, effective, and affordable treatment of AD. The nose-to-brain drug delivery approach holds a great potential to access the brain without any hindrance of BBB and result in higher bioavailability thus better therapeutic efficacy of anti-AD drugs.

AREAS COVERED

The present review article highlighted the current facts and worldwide statistics of AD and its detailed etiology. Followed by barriers to brain delivery, nose-to-brain delivery, their limitations, and amalgamation with various novel carrier systems. We have emphasized recent advancements in nose-to-brain delivery using mucoadhesive, stimuli-responsive carriers, polymeric nanoparticles, lipid nanoparticles, protein/peptide delivery for treatment of AD.

EXPERT OPINION

The available therapies are symptomatic, mitigate the symptoms of AD at the initial stages. In this lieu, nose-to-brain delivery has the ability to overcome these limitations and increase drug bioavailability in the brain. Various novel strategies including stimuli-responsive systems, nanoparticles, etc. enhance the nasal drug permeation, protects the drug, and enhance its therapeutic potency. Although, successful preclinical data does not assure the clinical success of the therapy and hence exhaustive clinical investigations are needed to make the therapy available for patients.

Cylindrical polymer brushes-anisotropic unimolecular micelle drug delivery system for enhancing the effectiveness of chemotherapy

Polymer systems can be designed into different structures and morphologies according to their physical and chemical performance requirements, and are considered as one of the most promising controlled delivery systems that can effectively improve the cancer therapeutic index. However, the majority of the polymer delivery systems are designed to be simple spherical nanostructures. To explore morphology/size-oriented delivery performance optimization, here, we synthesized three novel cylindrical polymer brushes (CPBs) by atom transfer radical polymerization (ATRP), which were cellulose-g-(CPT-b-OEGMA) (CCO) with different lengths (~86, ~40, and ~21 nm). The CPBs are composed of bio-degradable cellulose as the carrier, poly(ethylene glycol) methyl ether methacrylate (OEGMA) as hydrophily block, and glutathione (GSH)-responsive hydrophobic camptothecin (CPT) monomer as loaded anticancer drug. By controlling the chain length of the initiator, three kinds of polymeric prodrugs with different lengths (CCO-1, CCO-2, and CCO-3) could be self-organized into unimolecular micelles in water. We carried out comparative studies of three polymers, whose results verified that the shorter CPBs exhibited higher drug release efficiency, more cellular uptake, and enhanced tumor permeability, accompanied by shortened blood circulation time and lower tumor accumulation. As evidenced by in vivo experiments, the shorter CPBs exhibited higher anti-tumor efficiency, revealing that the size advantage has a higher priority than the anisotropic structure advantage. This provided vital information as to design an anisotropic polymer-based drug delivery system for cancer therapy.

Enhanced Proapoptotic Effects of Water Dispersed Complexes of 4-Thiazolidinone-Based Chemotherapeutics with a PEG-Containing Polymeric Nanocarrier

AIM

To study whether water formulation of the complex of 4-thiazolidinone derivatives with a PEG-containing polymeric nanocarrier enhances their pro-apoptotic action towards rat glioma C6 cells.

METHODS

Mechanisms of antineoplastic effects of 4-thiazolidinone derivatives were investigated in vitro with rat glioma C6 cells. Cell nativity, cell cycling pattern, and Annexin V expression were evaluated and DNA damage was estimated by DNA comet analysis. A novel water-based formulation of 4-thiazolidinone derivatives complexed with a polymeric nanocarrier was utilized for enhancing pro-apoptotic action towards C6 cells.

RESULTS

The studied 4-thiazolidinone derivatives use apoptosis mechanisms for killing rat glioma C6 cells, as confirmed by FACS analysis of these cells in pre-G1 stage, the appearance of Annexin V positive C6 cells, and an increased number of DNA comets of higher classes. Complexation of the studied compounds with a PEG-containing polymeric nanocarrier significantly increased pro-apoptotic effects in rat glioma C6 cells measured by all methods mentioned above.

CONCLUSION

Complexation of 4-thiazolidinone derivatives with a PEG-containing polymeric nanocarrier provided them with water solubility and enhanced pro-apoptotic effects in rat glioma C6 cells.