Thermo-targeted drug delivery of geldanamycin to hyperthermic tumor margins with diblock elastin-based biopolymers

Unfolded Protein Response Signaling in Liver Disorders: A 2023 Updated Review

Endoplasmic reticulum (ER) is the site for synthesis and folding of secreted and transmembrane proteins. Disturbance in the functioning of ER leads to the accumulation of unfolded and misfolded proteins, which finally activate the unfolded protein response (UPR) signaling. The three branches of UPR-IRE1 (Inositol requiring enzyme 1), PERK (Protein kinase RNA-activated (PKR)-like ER kinase), and ATF6 (Activating transcription factor 6)-modulate the gene expression pattern through increased expression of chaperones and restore ER homeostasis by enhancing ER protein folding capacity. The liver is a central organ which performs a variety of functions which help in maintaining the overall well-being of our body. The liver plays many roles in cellular physiology, blood homeostasis, and detoxification, and is the main site at which protein synthesis occurs. Disturbance in ER homeostasis is triggered by calcium level imbalance, change in redox status, viral infection, and so on. ER dysfunction and subsequent UPR signaling participate in various hepatic disorders like metabolic (dysfunction) associated fatty liver disease, liver cancer, viral hepatitis, and cholestasis. The exact role of ER stress and UPR signaling in various liver diseases is not fully understood and needs further investigation. Targeting UPR signaling with drugs is the subject of intensive research for therapeutic use in liver diseases. The present review summarizes the role of UPR signaling in liver disorders and describes why UPR regulators are promising therapeutic targets.

Recent Progress in Proteins-Based Micelles as Drug Delivery Carriers

Proteins-derived polymeric micelles have gained attention and revolutionized the biomedical field. Proteins are considered a favorable choice for developing micelles because of their biocompatibility, harmlessness, greater blood circulation and solubilization of poorly soluble drugs. They exhibit great potential in drug delivery systems as capable of controlled loading, distribution and function of loaded agents to the targeted sites within the body. Protein micelles successfully cross biological barriers and can be incorporated into various formulation designs employed in biomedical applications. This review emphasizes the recent advances of protein-based polymeric micelles for drug delivery to targeted sites of various diseases. Most studied protein-based micelles such as soy, gelatin, casein and collagen are discussed in detail, and their applications are highlighted. Finally, the future perspectives and forthcoming challenges for protein-based polymeric micelles have been reviewed with anticipated further advances.

ATP/Hyals dually responsive core-shell hyaluronan/chitosan-based drug nanocarrier for potential application in breast cancer therapy

The stability of self-assembled drug nanocarriers during blood circulation and the controlled intracellular drug delivery are two challenges in cancer therapy. In this paper, we constructed an adenosine triphosphate (ATP)/hyaluronidase(Hyals) dually responsive core-shell hyaluronan/chitosan-based drug nanocarrier for breast cancer therapy, using SNX-loaded 3-fluoro-4-carboxyphenylboronic acid-conjugated quaternary ammonium chitosan nanoparticles (SNX@HTCC-FPBA NPs) as the core and crosslinked polyethylene glycol-/methacrylate-modified hyaluronic acid (mHA-PEG) as the shell. The formed SNX@HTCC-FPBA/mHA-PEG NPs were stable against salt ion strength, pH values and human plasma mimicking the bloodstream, but ATP/Hyals dually sensitive with a drug delivery of 85% within 48 h in the mimicking intracellular environment of breast cancer cells. These nanoparticles showed a low hemolysis of less than 3%, a high resistance to bovine serum albumin adsorption of 0.06 mg/mg, and an efficient internalization by two breast cancer cell lines (MCF-7 and MDA-MB-453). The cell culture indicated that they were friendly to human skin fibroblasts, but presented a close IC₅₀ value to SNX for MCF-7 (0.14 μg mL^-1) and MDA-MB-453 (0.05 μg mL^-1) at 48 h, respectively. Thus, SNX@HTCC-FPBA/mHA-PEG NPs were potential drug nanocarriers for breast tumor therapy.

Smart stimuli-responsive biopolymeric nanomedicines for targeted therapy of solid tumors

Solid tumors form a permissive microenvironment with irregular features, including high pressured tumor interstitial fluid with acidic pH, co-adaptation of cancer cells with other cells like the immune system cells, abnormal metabolism and anomalous overexpression of various pieces of molecular machinery. The functional expressions of several oncomarkers in different solid tumors have led to the development of targeted drug-delivery systems (DDSs). As a new class of DDSs, stimuli-responsive nanomedicines (SRNMs) have been developed using advanced nanobiomaterials such as biopolymers that show excellent biocompatibility with low inherent immunogenicity. In this review, we aim to overview different types of SRNMs, present deep insights into the stimuli-responsive biopolymers and discuss the most up-to-date progress in the design and development of SRNMs used as advanced DDSs for targeted therapy of cancer.

The role of HSP90 molecular chaperones in hepatocellular carcinoma

Misfolded proteins have enhanced formation of toxic oligomers and nonfunctional protein copies lead to recruiting wild-type protein types. Heat shock protein 90 (HSP90) is a molecular chaperone generated by cells that are involved in many cellular functions through regulation of folding and/or localization of large multi-protein complexes as well as client proteins. HSP90 can regulate a number of different cellular processes including cell proliferation, motility, angiogenesis, signal transduction, and adaptation to stress. HSP90 makes the mutated oncoproteins able to avoid misfolding and degradation and permits the malignant transformation. As a result, HSP90 is an important factor in several signaling pathways associated with tumorigenicity, therapy resistance, and inhibiting apoptosis. Clinically, the upregulation of HSP90 expression in hepatocellular carcinoma (HCC) is linked with advanced stages and inappropriate survival in cases suffering from this kind of cancer. The present review comprehensively assesses HSP90 functions and its possible usefulness as a potential diagnostic biomarker and therapeutic option for HCC.

Thermoresponsive gating membranes embedded with liquid crystal(s) for pulsatile transdermal drug delivery: An overview and perspectives

Due to the circadian rhythm regulation of almost every biological process in the human body, physiological and biochemical conditions vary considerably over the course of a 24-h period. Thus, optimal drug delivery and therapy should be effectively controlled to achieve the desired therapeutic plasma concentrations and therapeutic drug responses at the required time according to chronopharmacological concepts, rather than continuous maintenance of constant drug concentrations for an extended time period. For many drugs, it is not always necessary to constantly deliver a drug into the human body under disease conditions due to rhythmic variations. Pulsatile drug delivery systems (PDDSs) have been receiving more attention in pharmaceutical development by providing a predetermined lag period, followed by a fast or rate-controlled drug release after application. PDDSs are characterized by a programmed drug release, which may release a drug at repeatable pulses to match the biological and clinical needs of a given disease therapy. This review article focuses on thermoresponsive gating membranes embedded with liquid crystals (LCs) for transdermal drug delivery using PDDS technology. In addition, the principal rationale and the advanced approaches for the use of PDDSs, the marketed products of chronotherapeutic DDSs with pulsatile function designed by various PDDS technologies, pulsatile drug delivery designed with thermoresponsive polymers, challenges and opportunities of transdermal drug delivery, and novel approaches of LC systems for drug delivery are reviewed and discussed. A brief overview of all academic research articles concerning single LC- or binary LC-embedded thermoresponsive membranes with a switchable on-off permeation function through topical application by an external temperature control, which may modulate the dosing interval and administration time according to the therapeutic needs of the human body, is also compiled and presented. In the near future, since thermal-based approaches have become a well-accepted method to enhance transdermal delivery of different water-soluble drugs and macromolecules, a combination of the thermal-assisted approach with thermoresponsive LCs membranes will have the potential to improve PDDS applications but still poses a great challenge.

Protein-Based Drug-Delivery Materials

There is a pressing need for long-term, controlled drug release for sustained treatment of chronic or persistent medical conditions and diseases. Guided drug delivery is difficult because therapeutic compounds need to survive numerous transport barriers and binding targets throughout the body. Nanoscale protein-based polymers are increasingly used for drug and vaccine delivery to cross these biological barriers and through blood circulation to their molecular site of action. Protein-based polymers compared to synthetic polymers have the advantages of good biocompatibility, biodegradability, environmental sustainability, cost effectiveness and availability. This review addresses the sources of protein-based polymers, compares the similarity and differences, and highlights characteristic properties and functionality of these protein materials for sustained and controlled drug release. Targeted drug delivery using highly functional multicomponent protein composites to guide active drugs to the site of interest will also be discussed. A systematical elucidation of drug-delivery efficiency in the case of molecular weight, particle size, shape, morphology, and porosity of materials will then be demonstrated to achieve increased drug absorption. Finally, several important biomedical applications of protein-based materials with drug-delivery function-including bone healing, antibiotic release, wound healing, and corneal regeneration, as well as diabetes, neuroinflammation and cancer treatments-are summarized at the end of this review.

Tumour eradication using synchronous thermal ablation and Hsp90 chemotherapy with protein engineered triblock biopolymer-geldanamycin conjugates

PURPOSE

Hepatocellular carcinoma (HCC) suffers high tumour recurrence rate after thermal ablation. Heat shock protein 90 (Hsp90) induced post-ablation is critical for tumour survival and progression. A combination therapy of thermal ablation and polymer conjugated Hsp90 chemotherapy was designed and evaluated for complete tumour eradication of HCC.

MATERIALS AND METHODS

A thermo-responsive, elastin-like polypeptide (ELP)-based tri-block biopolymer was developed and conjugated with a potent Hsp90 inhibitor, geldanamycin (GA). The anti-cancer efficacy of conjugates was evaluated in HCC cell cultures with and without hyperthermia (43 °C). The conjugates were also administered twice weekly in a murine HCC model as a single treatment or in combination with single electrocautery as the ablation method.

RESULTS

ELP-GA conjugates displayed enhanced cytotoxicity in vitro and effective heat shock inhibition under hyperthermia. The conjugates alone significantly slowed the tumour growth without systemic toxicity. Four doses of thermo-responsive ELP-GA conjugates with concomitant simple electrocautery accomplished significant Hsp90 inhibition and sustained tumour suppression.

CONCLUSION

Hsp90 inhibition plays a key role in preventing the recurrence of HCC, and the combination of ablation with targeted therapy holds great potential to improve prognosis and survival of HCC patients.

Thermoresponsive self-assembly of nanostructures from a collagen-like peptide-containing diblock copolymer

Temperature-triggered formation of nanostructures with distinct biological activity offers opportunities in selective modification of matrices and in drug delivery. Toward these ends, diblock polymers comprising poly(diethylene glycol methyl ether methacrylate) (PDEGMEMA) conjugated to a triple helix-forming collagen-like peptide were produced. Triggered by the collapse of the thermoresponsive domain above its LCST, the conjugate undergoes a reversible transition in aqueous solution to form well-defined nanovesicles with diameters of approximately 100 nm, with a transition temperature of 37 °C. The incorporation of CLP domains in these nanostructures may offer opportunities for the selective targeting of collagen-containing matrices.

Controlled release from recombinant polymers

Recombinant polymers provide a high degree of molecular definition for correlating structure with function in controlled release. The wide array of amino acids available as building blocks for these materials lend many advantages including biorecognition, biodegradability, potential biocompatibility, and control over mechanical properties among other attributes. Genetic engineering and DNA manipulation techniques enable the optimization of structure for precise control over spatial and temporal release. Unlike the majority of chemical synthetic strategies used, recombinant DNA technology has allowed for the production of monodisperse polymers with specifically defined sequences. Several classes of recombinant polymers have been used for controlled drug delivery. These include, but are not limited to, elastin-like, silk-like, and silk-elastinlike proteins, as well as emerging cationic polymers for gene delivery. In this article, progress and prospects of recombinant polymers used in controlled release will be reviewed.

Elastin-like polypeptides and their applications in anticancer drug delivery systems: a review

Elastin-like polypeptides (ELPs) are large molecular weight biopolymers. They have been widely studied as macromolecular carriers for targeted delivery of drugs. The aim of the present article is to review the available information on ELPs (including our recent investigations), their properties, drug delivery applications to tumor sites and future perspectives. This review also provides information on the use of short synthetic ELPs for making ELP-drug conjugates, for targeted delivery of anticancer drugs. In the present review we also focus on the point that short ELPs can also be used for targeting anticancer drugs to tumor sites as they behave similar to long ELPs regarding their capacity to undergo inverse temperature transition (ITT) behavior.

Application of elastin-mimetic recombinant proteins in chemotherapeutics delivery, cellular engineering, and regenerative medicine

With the remarkable increase in the fields of biomedical engineering and regenerative medicine, biomaterial design has become an indispensable approach for developing the biocompatible carriers for drug or gene cargo and extracellular matrix (ECM) for cell survival, proliferation and differentiation. Native ECM materials derived from animal tissues were believed to be the best choices for tissue engineering. However, possible pathogen contamination by cellular remnants from foreign animal tissues is an unavoidable issue that has limited the use of native ECM for human benefit. Some synthetic polymers have been used as alternative materials for manufacturing native ECM because of the biodegradability and ease of large-scale production of the polymers. However, the inherent polydispersity of the polymers causes batch-to-batch variation in polymer composition and possible cytotoxic interactions between chemical matrices and neighboring cells or tissues have not yet been fully resolved. Elastin-like proteins (ELPs) are genetically engineered biopolymers modeled after the naturally occurring tropoelastin and have emerged as promising materials for biomedical applications because they are biocompatible, non-immunogenic and biodegradable, and their composition, mechanical stiffness and even fate within the cell can be controlled at the gene level. This commentary highlights the recent progresses in the development of the ELP-based recombinant proteins that are being increasingly used for the delivery of chemotherapeutics and to provide a cell-friendly ECM environment.