Thermoresponsive Supramolecular Chemotherapy by "V"-Shaped Armed β-Cyclodextrin Star Polymer to Overcome Drug Resistance

Recent Progress of Supramolecular Chemotherapy Based on Host-Guest Interactions

Chemotherapy is widely recognized as an effective approach for treating cancer due to its ability to eliminate cancer cells using chemotherapeutic drugs. However, traditional chemotherapy suffers from various drawbacks, including limited solubility and stability of drugs, severe side effects, low bioavailability, drug resistance, and challenges in tracking treatment efficacy. These limitations greatly hinder its widespread clinical application. In contrast, supramolecular chemotherapy, which relies on host-guest interactions, presents a promising alternative by offering highly efficient and minimally toxic anticancer drug delivery. In this review, an overview of recent advancements in supramolecular chemotherapy based on host-guest interactions is provided. The significant role it plays in guiding cancer therapy is emphasized. Drawing on a wealth of cutting-edge research, herein, a timely and valuable resource for individuals interested in the field of supramolecular chemotherapy or cancer therapy, is presented. Furthermore, this review contributes to the progression of the field of supramolecular chemotherapy toward clinical application.

Facile synthesis of Fe2O3, Fe2O3@CuO and WO3 nanoparticles: characterization, structure determination and evaluation of their biological activity

Due to their high specific surface area and its characteristic's functionalized nanomaterials have great potential in medical applications specialty, as an anticancer. Herein, functional nanoparticles (NPs) based on iron oxide Fe2O3, iron oxide modified with copper oxide Fe2O3@CuO, and tungsten oxide WO3 were facile synthesized for biomedical applications. The obtained nanomaterials have nanocrystal sizes of 35.5 nm for Fe2O3, 7 nm for Fe2O3@CuO, and 25.5 nm for WO3. In addition to octahedral and square nanoplates for Fe2O3, and WO3; respectively. Results revealed that Fe2O3, Fe2O3@CuO, and WO3 NPs showed remarked anticancer effects versus a safe effect on normal cells through cytotoxicity test using MTT-assay. Notably, synthesized NPs e.g. our result demonstrated that Fe2O3@CuO exhibited the lowest IC50 value on the MCF-7 cancer cell line at about 8.876 µg/ml, compared to Fe2O3 was 12.87 µg/ml and WO3 was 9.211 µg/ml which indicate that the modification NPs Fe2O3@CuO gave the highest antiproliferative effect against breast cancer. However, these NPs showed a safe mode toward the Vero normal cell line, where IC50 were monitored as 40.24 µg/ml for Fe2O3, 21.13 µg/ml for Fe2O3@CuO, and 25.41 µg/ml for WO3 NPs. For further evidence. The antiviral activity using virucidal and viral adsorption mechanisms gave practiced effect by viral adsorption mechanism and prevented the virus from replicating inside the cells. Fe2O3@CuO and WO3 NPs showed a complete reduction in the viral load synergistic effect of combinations between the tested two materials copper oxide instead of iron oxide alone. Interestingly, the antimicrobial efficiency of Fe2O3@CuO NPs, Fe2O3NPs, and WO3NPs was evaluated using E. coli, S. aureus, and C. albicans pathogens. The widest microbial inhibition zone (ca. 38.45 mm) was observed with 250 mg/ml of WO3 NPs against E. coli, whereas using 40 mg/ml of Fe2O3@CuO NPS could form microbial inhibition zone ca. 32.86 mm against S. aureus. Nevertheless, C. albicans was relatively resistant to all examined NPs. The superior biomedical activities of these nanostructures might be due to their unique features and accepted evaluations.

Cyclodextrins and derivatives in drug delivery: New developments, relevant clinical trials, and advanced products

Cyclodextrins (CD) and derivatives are functional excipients that can improve the bioavailability of numerous drugs. Because of their drug solubility improving properties they are used in many pharmaceutical products. Furthermore, the stability of small molecular drugs can be improved by the incorporation in CDs and an unpleasant taste and smell can be masked. In addition to well-established CD derivatives including hydroxypropyl-β-CD, hydroxypropyl-γ-CD, methylated- β-CD and sulfobutylated- β-CD, there are promising new derivatives in development. In particular, CD-based polyrotaxanes exhibiting cellular uptake enhancing properties, CD-polymer conjugates providing sustained drug release, enhanced cellular uptake, and mucoadhesive properties, and thiolated CDs showing mucoadhesive, in situ gelling, as well as permeation and cellular uptake enhancing properties will likely result in innovative new drug delivery systems. Relevant clinical trials showed various new applications of CDs such as the formation of CD-based nanoparticles, stabilizing properties for protein drugs or the development of ready-to-use injection systems. Advanced products are making use of various benefical properties of CDs at the same time. Within this review we provide an overview on these recent developments and take an outlook on how this class of excipients will further shape the landscape of drug delivery.

Controllable Star Cationic Poly(Disulfide)s Achieve Genetically Cascade Catalytic Therapy by Delivering Bifunctional Fusion Plasmids

The absence of effective delivery vectors and suitable multifunctional plasmids limits cancer gene therapy development. The star cationic poly(disulfide)s with β-cyclodextrin cores (termed β-CD-g-PSSn ) for caveolae-mediated endocytosis are designed and prepared via mild and controllable disulfide exchange polymerization for high-efficacy cancer therapy. Then, β-CD-g-PSSn /pDNA complexes are transported to the Golgi apparatus and endoplasmic reticulum. Disulfides in β-CD-g-PSSn vectors are degraded by glutathione in tumor cells, which not only promotes intracellular pDNA release but also reduces in vitro and in vivo toxicity. One bifunctional fusion plasmid pCATKR, which expresses catalase (CAT) fused to KillerRed (KR) (CATKR) in the same target cell, is also proposed for genetically cascade catalytic therapy. When compared with pCAT-KR (plasmid expressing CAT and KR separately in the same cell), delivered pCATKR decomposes hydrogen peroxide, alleviates tumor hypoxia more effectively, generates stronger reactive oxygen species (ROS) capabilities under moderate irradiation, and leads to robust antitumor cascade photodynamic effects. These impressive results are attributed to fusion protein design, which shortens the distance between CAT and KR catalytic centers and leads to improved ROS production efficiency. This work provides a promising strategy by delivering a catalytic cascade functional plasmid via a high-performance vector with biodegradable and caveolae-mediated endocytosis characteristics.

Supramolecular host-guest nanosystems for overcoming cancer drug resistance

Cancer drug resistance has become one of the main challenges for the failure of chemotherapy, greatly limiting the selection and use of anticancer drugs and dashing the hopes of cancer patients. The emergence of supramolecular host-guest nanosystems has brought the field of supramolecular chemistry into the nanoworld, providing a potential solution to this challenge. Compared with conventional chemotherapeutic platforms, supramolecular host-guest nanosystems can reverse cancer drug resistance by increasing drug uptake, reducing drug efflux, activating drugs, and inhibiting DNA repair. Herein, we summarize the research progress of supramolecular host-guest nanosystems for overcoming cancer drug resistance and discuss the future research direction in this field. It is hoped that this review will provide more positive references for overcoming cancer drug resistance and promoting the development of supramolecular host-guest nanosystems.

Preparation, thermal response mechanisms and biomedical applications of thermosensitive hydrogels for drug delivery

INTRODUCTION

Drug treatment is one of the main ways of coping with disease today. For the disadvantages of drug management, thermosensitive hydrogel is used as a countermeasure, which can realize the simple sustained release of drugs and the controlled release of drugs in complex physiological environments.

AREAS COVERED

This paper talks about thermosensitive hydrogels that can be used as drug carriers. The common preparation materials, material forms, thermal response mechanisms, characteristics of thermosensitive hydrogels for drug release and main disease treatment applications are reviewed.

EXPERT OPINION

When thermosensitive hydrogels are used as drug loading and delivery platforms, desired drug release patterns and release profiles can be tailored by selecting raw materials, thermal response mechanisms, and material forms. The properties of hydrogels prepared from synthetic polymers will be more stable than natural polymers. Integrating multiple thermosensitive mechanisms or different kinds of thermosensitive mechanisms on the same hydrogel is expected to realize the spatiotemporal differential delivery of multiple drugs under temperature stimulation. The industrial transformation of thermosensitive hydrogels as drug delivery platforms needs to meet some important conditions.

Cyclodextrin-Based Polymeric Drug Delivery Systems for Cancer Therapy

Cyclodextrins (CDs) are one of the most extensively studied cyclic-oligosaccharides due to their low toxicity, good biodegradability and biocompatibility, facile chemical modification, and unique inclusion capacity. However, problems such as poor pharmacokinetics, plasma membrane disruption, hemolytic effects and a lack of target specificity still exist for their applications as drug carriers. Recently, polymers have been introduced into CDs to combine the advantages of both biomaterials for the superior delivery of anticancer agents in cancer treatment. In this review, we summarize four types of CD-based polymeric carriers for the delivery of chemotherapeutics or gene agents for cancer therapy. These CD-based polymers were classified based on their structural properties. Most of the CD-based polymers were amphiphilic with the introduction of hydrophobic/hydrophilic segments and were able to form nanoassemblies. Anticancer drugs could be included in the cavity of CDs, encapsulated in the nanoparticles or conjugated on the CD-based polymers. In addition, the unique structures of CDs enable the functionalization of targeting agents and stimuli-responsive materials to realize the targeting and precise release of anticancer agents. In summary, CD-based polymers are attractive carriers for anticancer agents.

Guest-host Relationship of Cyclodextrin and its Pharmacological Benefits

Many methods, including solid dispersion, micellization, and inclusion complexes, have been employed to increase the solubility of potent drugs. Beta-cyclodextrin (βCD) is a cyclic oligosaccharide consisting of seven glucopyranoside molecules, and is a widely used polymer for formulating soluble inclusion complexes of hydrophobic drugs. The enzymatic activity of Glycosyltransferase or α-amylase converts starch or its derivatives into a mixture of cyclodextrins. The βCD units are characterized by α -(1-4) glucopyranose bonds. Cyclodextrins possess certain properties that make them very distinctive because of their toroidal or truncated cage-like supramolecular configurations with multiple hydroxyl groups at each end. This allowed them to encapsulate hydrophobic compounds by forming inclusion complexes without losing their solubility in water. Chemical modifications and newer derivatives, such as methylated βCD, more soluble hydroxyl propyl methyl βCD, and sodium salts of sulfobutylether-βCD, known as dexolve® or captisol®, have envisaged the use of CDs in various pharmaceutical, medical, and cosmetic industries. The successful inclusion of drug complexes has demonstrated improved solubility, bioavailability, drug resistance reduction, targeting, and penetration across skin and brain tissues. This review encompasses the current applications of β-CDs in improving the disease outcomes of antimicrobials and antifungals as well as anticancer and anti-tubercular drugs.

Engineered upconversion nanocarriers for synergistic breast cancer imaging and therapy: Current state of art

Breast cancer is the most common type of cancer in women and is the second leading cause of cancer-related deaths worldwide. Early diagnosis and effective therapeutic interventions are critical determinants that can improve survival and quality of life in breast cancer patients. Nanotheranostics are emerging interventions that offer the dual benefit of in vivo diagnosis and therapeutics through a single nano-sized carrier. Rare earth metal-doped upconversion nanoparticles (UCNPs) with their ability to convert near-infrared light to visible light or UV light in vivo settings have gained special attraction due to their unique luminescence and tumor-targeting properties. In this review, we have discussed applications of UCNPs in drug and gene delivery, photothermal therapy (PTT), photodynamic therapy (PDT) and tumor targeting in breast cancer. Further, present challenges and future opportunities for UCNPs in breast cancer treatment have also been mentioned.

Emerging nanotechnology-based therapeutics to combat multidrug-resistant cancer

Cancer often develops multidrug resistance (MDR) when cancer cells become resistant to numerous structurally and functionally different chemotherapeutic agents. MDR is considered one of the principal reasons for the failure of many forms of clinical chemotherapy. Several factors are involved in the development of MDR including increased expression of efflux transporters, the tumor microenvironment, changes in molecular targets and the activity of cancer stem cells. Recently, researchers have designed and developed a number of small molecule inhibitors and derivatives of natural compounds to overcome various mechanisms of clinical MDR. Unfortunately, most of the chemosensitizing approaches have failed in clinical trials due to non-specific interactions and adverse side effects at pharmacologically effective concentrations. Nanomedicine approaches provide an efficient drug delivery platform to overcome the limitations of conventional chemotherapy and improve therapeutic effectiveness. Multifunctional nanomaterials have been found to facilitate drug delivery by improving bioavailability and pharmacokinetics, enhancing the therapeutic efficacy of chemotherapeutic drugs to overcome MDR. In this review article, we discuss the major factors contributing to MDR and the limitations of existing chemotherapy- and nanocarrier-based drug delivery systems to overcome clinical MDR mechanisms. We critically review recent nanotechnology-based approaches to combat tumor heterogeneity, drug efflux mechanisms, DNA repair and apoptotic machineries to overcome clinical MDR. Recent successful therapies of this nature include liposomal nanoformulations, cRGDY-PEG-Cy5.5-Carbon dots and Cds/ZnS core–shell quantum dots that have been employed for the effective treatment of various cancer sub-types including small cell lung, head and neck and breast cancers.

Steric Effects in the Deposition Mode and Drug-Delivering Efficiency of Nanocapsule-Based Multilayer Films

Using surface-initiated atom transfer radical polymerization (ATRP), block polymers with a series of quaternization degrees were coated on the surface of silica nanocapsules (SNCs) by the "grafting-from" technique. Molnupiravir, an antiviral medicine urgently approved for the treatment of SARS-CoV-2, was encapsulated in polymer-coated SNCs and further incorporated into well-defined films with polystyrene sulfonate (PSS) homopolymers by layer-by-layer (LBL) self-assembly via electrostatic interactions. We investigated the impact of the quaternization degree of the polymers and steric hindrance of functional groups on the growth mode, swelling/deswelling transition, and drug-delivering efficiency of the obtained LBL films. The SNCs were derived from coronas of parent block polymers of matched molecular weights-poly(N-isopropylacrylamide)-block-poly(N,N-dimethylaminoethyl methacrylate) (PNIPAM-b-PDMAEMA)-by quaternization with methyl sulfate. As revealed by the data results, SNCs with coronas with higher quaternization degrees resulted in a larger layering distance of the film structure because of weaker ionic pairing (due to the presence of a bulky methyl spacer) between SNCs and PSS. Interestingly, when comparing the drug release profile of the encapsulated drugs from SNC-based films, the release rate was slower in the case of capsule coronas with higher quaternization degrees because of the larger diffusion distance of the encapsulated drugs and stronger hydrophobic-hydrophobic interactions between SNCs and drug molecules.

Supramolecular Helical Miktoarm Star Polymers

We report a hydrogen-bonded supramolecular miktoarm star polymer containing three distinct helical arms. Our design involves two helical poly(methacrylamide) arms connected by a barbituric acid (Ba) at the center, prepared through the reversible addition-fragmentation chain-transfer polymerization with a bifunctional agent. Together with a telechelic helical poly(isocyanide) end-functionalized with a Hamilton Wedge (HW) that is complementary to Ba, the two components assemble into an AB₂-type star copolymer. The assembly is driven by the hydrogen bonding between HW and Ba, which is quantified by ¹H NMR titration and isothermal titration calorimetry. Gel-permeation chromatography provides evidence for the formation of the desired miktoarm star architecture. This strategy of site-specific functionalization on helical polymers provides a modular approach to preparing nonlinear supramolecular ensembles with topologically diverse building blocks.

Stimuli-responsive cyclodextrin-based supramolecular assemblies as drug carriers

Cyclodextrins (CDs) are widely employed in biomedical applications because of their unique structures. Various biomedical applications can be achieved in a spatiotemporally controlled manner by integrating the host-guest chemistry of CDs with stimuli-responsive functions. In this review, we summarize the recent advances in stimuli-responsive supramolecular assemblies based on the host-guest chemistry of CDs. The stimuli considered in this review include endogenous (pH, redox, and enzymes) and exogenous stimuli (light, temperature, and magnetic field). We mainly discuss the mechanisms of the stimuli-responsive ability and present typical designs of the corresponding supramolecular assemblies for drug delivery and other potential biomedical applications. The limitations and perspectives of CD-based stimuli-responsive supramolecular assemblies are discussed to further promote the translation of laboratory products into clinical applications.

Emerging Nano-Based Strategies Against Drug Resistance in Tumor Chemotherapy

Drug resistance is the most significant causes of cancer chemotherapy failure. Various mechanisms of drug resistance include tumor heterogeneity, tumor microenvironment, changes at cellular levels, genetic factors, and other mechanisms. In recent years, more attention has been paid to tumor resistance mechanisms and countermeasures. Nanomedicine is an emerging treatment platform, focusing on alternative drug delivery and improved therapeutic effectiveness while reducing side effects on normal tissues. Here, we reviewed the principal forms of drug resistance and the new possibilities that nanomaterials offer for overcoming these therapeutic barriers. Novel nanomaterials based on tumor types are an excellent modality to equalize drug resistance that enables gain more rational and flexible drug selectivity for individual patient treatment. With the emergence of advanced designs and alternative drug delivery strategies with different nanomaterials, overcome of multidrug resistance shows promising and opens new horizons for cancer therapy. This review discussed different mechanisms of drug resistance and recent advances in nanotechnology-based therapeutic strategies to improve the sensitivity and effectiveness of chemotherapeutic drugs, aiming to show the advantages of nanomaterials in overcoming of drug resistance for tumor chemotherapy, which could accelerate the development of personalized medicine.

Structure-antitumor activity relationships of tripodal imidazolium-amino acid based salts. Effect of the nature of the amino acid, amide substitution and anion

The antitumor activity of imidazolium salts is highly dependent upon their lipophilicity that can be tuned by the introduction of different hydrophobic substituents on the nitrogen atoms of the imidazolium ring of the molecule. Taking this into consideration, we have synthesized and characterized a series of tripodal imidazolium salts derived from L-valine and L-phenylalanine containing different hydrophobic groups and tested them against four cancer cell lines at physiological and acidic pH. At acidic pH (6.2) the anticancer activity of some of the tripodal compounds changes dramatically, and this parameter is crucial to control their cytotoxicity and selectivity. Moreover, several of these compounds displayed selectivity against the control healthy cell line higher than four. The transmembrane anion transport studies revealed moderate transport abilities suggesting that the observed biological activity is likely not the result of just their transport activity. The observed trends in biological activity at acidic pH agree well with the results for the CF leakage assay. These results strongly suggest that this class of compounds can serve as potential chemotherapeutic agents.

Engineering nanotheranostic strategies for liver cancer

The incidence and mortality of hepatocellular carcinoma have continued to increase over the last few years, and the medicine-based outlook of patients is poor. Given great ideas from the development of nanotechnology in medicine, especially the advantages in the treatments of liver cancer. Some engineering nanoparticles with active targeting, ligand modification, and passive targeting capacity achieve efficient drug delivery to tumor cells. In addition, the behavior of drug release is also applied to the drug loading nanosystem based on the tumor microenvironment. Considering clinical use of local treatment of liver cancer, in situ drug delivery of nanogels is also fully studied in orthotopic chemotherapy, radiotherapy, and ablation therapy. Furthermore, novel therapies including gene therapy, phototherapy, and immunotherapy are also applied as combined therapy for liver cancer. Engineering nonviral polymers to function as gene delivery vectors with increased efficiency and specificity, and strategies of co-delivery of therapeutic genes and drugs show great therapeutic effect against liver tumors, including drug-resistant tumors. Phototherapy is also applied in surgical procedures, chemotherapy, and immunotherapy. Combination strategies significantly enhance therapeutic effects and decrease side effects. Overall, the application of nanotechnology could bring a revolutionary change to the current treatment of liver cancer.

AuNPs Decorated PLA Stereocomplex Micelles for Synergetic Photothermal and Chemotherapy

A unique platform for combined photothermal and chemotherapy using PLA stereocomplex (PLA SC) micelles-induced hybrid gold nanocarriers is designed. The PLA SC micelles, made from the self-assembly of poly(ethylene glycol)-block-poly(l-lactide) (PEG-PLLA) and poly(2-(dimethylamino) ethyl methacrylate)-block-poly(d-lactide) (PDMAEMA-PDLA), for the first time are used as a template to fabricate the hybrid PLA SC@Au core-shell nanocarriers, in which the anticancer drugs are encapsulated within the core, while the Au nanoparticles are tethered in the shell via the in situ reduction of AuCl₄ ^- by PDMAEMA. The obtained PLA SC@Au hybrid nanocarriers exhibit low toxicity and remarkable photothermal effect. Upon near-infrared laser irradiation, the on-site photothermal therapy can further induce an accelerated drug release from the hybrid nanocarrier reservoir via hyperthermia heating of the nanocarriers, thus leading to a synergistic photothermal and chemotherapy toward a significantly improved efficacy in tumor shrinkage. The as-designed PLA SC@Au hybrid nanocarriers, with their biocompatible compositions, dual-drug delivery characteristics, and combined photothermal/chemotherapy, show high potential as a novel platform for cancer treatment.

Phosphatidylinositol-3,4,5-trisphosphate dependent Rac exchange factor 1 is a diagnostic and prognostic biomarker for hepatocellular carcinoma

BACKGROUND

Phosphatidylinositol-3,4,5-trisphosphate dependent Rac exchange factor 1 (P-Rex1) was reported to be a risk factor in several cancers, including breast cancer, lung cancer, and melanoma, but its expression and role in hepatocellular carcinoma (HCC) have not yet been fully studied.

AIM

To explore the expression of P-Rex1 in HCC, and further evaluate its potential application in the diagnosis and prognosis of HCC, especially in hepatitis B virus (HBV)-related patients.

METHODS

P-Rex1 expression in HCC was evaluated by real-time-quantitative polymerase chain reaction. The expression of P-Rex1 was subjected to correlation analysis with clinical features, such as lymph node invasion, distant metastasis, HBV infection, patient's age and gender. Receiver operating characteristic analysis was used to examine the potential role of P-Rex1 as a diagnostic biomarker in HCC. Kaplan-Meier analysis was used to determine the association between P-Rex1 expression and overall survival, progression-free survival and relapse-free survival. Bioinformatic analysis was used to validate the clinical findings.

RESULTS

P-Rex1 expression was significantly increased in HCC tumors than adjacent tissues. The expression of P-Rex1 was higher in HCC patients with lymph node invasion, distant metastasis, HBV infection and positive alpha-fetoprotein, respectively. The receiver operating characteristic analysis showed that P-Rex1 was a diagnostic biomarker with a higher area under the curve value, especially in patients with HBV infection. Survival analysis showed that patients with higher P-Rex1 expression had a favorable survival rate, even in early-stage patients.

CONCLUSION

P-Rex1 expression was highly increased in HCC, and the expression level of P-Rex1 was positively correlated with tumor progression. P-Rex1 has a higher efficiency in the diagnosis of HBV-related HCC, and could also be used as a favorable prognostic factor for HCC patients.

Comprehensive assessment of Nile tilapia skin collagen sponges as hemostatic dressings

Nile tilapia skin collagen sponge was fabricated by lyophilization and cross-linked with 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide in the presence of N-hydroxysuccinimide (EDC/NHS). The physicochemical properties were examined. The EDC/NHS cross-linked collagen sponge presented an enhanced water absorption capacity. In addition, biocompatibility and hemostatic efficiency were evaluated by acute systemic toxicity assay, dermal irritation test, intradermal reaction test, sensitization test, cytotoxicity, blood clotting assay in vitro, and liver and femoral artery hemorrhage models in vivo. Results showed that the produced collagen sponges before and after EDC/NHS cross-linking had excellent biocompatibility. Furthermore, EDC/NHS cross-linking promoted fibroblast cells viability and proliferation reflected by the MTT reduction assay. Meanwhile, EDC/NHS cross-linked collagen sponge exhibited the best blood clotting ability and hemostatic efficiency in rat femoral artery hemorrhage model in comparison with non-crosslinked and commercial collagen sponges. Our results demonstrated that the fabricated collagen sponges could be used as perfect hemostatic dressings.

Thermo-responsive polymers: Applications of smart materials in drug delivery and tissue engineering

Synthetic polymers are attracting great attention in the last decades for their use in the biomedical field as nanovectors for controlled drug delivery, hydrogels and scaffolds enabling cell growth. Among them, polymers able to respond to environmental stimuli have been recently under growing consideration to impart a "smart" behavior to the final product, which is highly desirable to provide it with a specific dynamic and an advanced function. In particular, thermo-responsive polymers, materials able to undergo a discontinuous phase transition or morphological change in response to a temperature variation, are among the most studied. The development of the so-called controlled radical polymerization techniques has paved the way to a high degree of engineering for the polymer architecture and properties, which in turn brought to a plethora of sophisticated behaviors for these polymers by simply switching the external temperature. These can be exploited in many different fields, from separation to advanced optics and biosensors. The aim of this review is to critically discuss the latest advances in the development of thermo-responsive materials for biomedical applications, including a highly controlled drug delivery, mediation of cell growth and bioseparation. The focus is on the structural and design aspects that are required to exploit such materials for cutting-edge applications in the biomedical field.

Current trends and challenges in cancer management and therapy using designer nanomaterials

Nanotechnology has the potential to circumvent several drawbacks of conventional therapeutic formulations. In fact, significant strides have been made towards the application of engineered nanomaterials for the treatment of cancer with high specificity, sensitivity and efficacy. Tailor-made nanomaterials functionalized with specific ligands can target cancer cells in a predictable manner and deliver encapsulated payloads effectively. Moreover, nanomaterials can also be designed for increased drug loading, improved half-life in the body, controlled release, and selective distribution by modifying their composition, size, morphology, and surface chemistry. To date, polymeric nanomaterials, metallic nanoparticles, carbon-based materials, liposomes, and dendrimers have been developed as smart drug delivery systems for cancer treatment, demonstrating enhanced pharmacokinetic and pharmacodynamic profiles over conventional formulations due to their nanoscale size and unique physicochemical characteristics. The data present in the literature suggest that nanotechnology will provide next-generation platforms for cancer management and anticancer therapy. Therefore, in this critical review, we summarize a range of nanomaterials which are currently being employed for anticancer therapies and discuss the fundamental role of their physicochemical properties in cancer management. We further elaborate on the topical progress made to date toward nanomaterial engineering for cancer therapy, including current strategies for drug targeting and release for efficient cancer administration. We also discuss issues of nanotoxicity, which is an often-neglected feature of nanotechnology. Finally, we attempt to summarize the current challenges in nanotherapeutics and provide an outlook on the future of this important field.

Recent Advances on Polymeric Beads or Hydrogels as Embolization Agents for Improved Transcatheter Arterial Chemoembolization (TACE)

Transcatheter arterial chemoembolization (TACE), aiming to block the hepatic artery for inhibiting tumor blood supply, became a popular therapy for hepatocellular carcinoma (HCC) patients. Traditional TACE formulation of anticancer drug emulsion in ethiodized oil (i.e., Lipiodol®) and gelatin sponge (i.e., Gelfoam®) had drawbacks on patient tolerance and resulted in undesired systemic toxicity, which were both significantly improved by polymeric beads, microparticles, or hydrogels by taking advantage of the elegant design of biocompatible or biodegradable polymers, especially amphiphilic polymers or polymers with both hydrophilic and hydrophobic chains, which could self-assemble into proposed microspheres or hydrogels. In this review, we aimed to summarize recent advances on polymeric embolization beads or hydrogels as TACE agents, with emphasis on their material basis of polymer architectures, which are important but have not yet been comprehensively summarized.

Recent Progress in Macromolecule-Anchored Hybrid Gold Nanomaterials for Biomedical Applications

Gold nanoparticles (AuNPs), with elegant thermal, optical, or chemical properties due to quantum size effects, may serve as unique species for therapeutic or diagnostic applications. It is worth mentioning that their small size also results in high surface activity, leading to significantly impaired stability, which greatly hinders their biomedical utilizations. To overcome this problem, various types of macromolecular materials are utilized to anchor AuNPs so as to achieve advanced synergistic effect by dispersing, protecting, and stabilizing the AuNPs in polymeric-Au hybrid self-assemblies. In this review, the most recent development of polymer-AuNP hybrid systems, including AuNPs@polymeric nanoparticles, AuNPs@polymeric micelle, AuNPs@polymeric film, and AuNPs@polymeric hydrogel are discussed with respect to their different synthetic strategies. These sophisticated materials with diverse functions, oriented toward biomedical applications, are further summarized into several active domains in the areas of drug delivery, gene delivery, photothermal therapy, antibacterials, bioimaging, etc. Finally, the possible approaches for future design of multifunctional polymer-AuNP hybrids by combining hybrid chemistry with biological interface science are proposed.

Biodegradable polyester unimolecular systems as emerging materials for therapeutic applications

Unimolecular micelles, as a class of single-molecular micelles, are structurally stable regardless of their concentrations or alterations of the outer environment such as pH, temperature, ion strength etc. in comparison with conventional polymeric micelles. Polyester unimolecular micelles are extensively applied in bio-medical fields because of their stability, biocompatibility, biodegradability, structural-controllabilty etc. In this review, the most recent developments in polyester unimolecular micelle designs in terms of Boltorn polymer H40 core, cyclodextrin, dendrimer or dendrimer-like polymer, or polyhedral oligomeric silsesquioxane (POSS) based polyester unimolecular micelles are presented. The significance and application in biomedical fields including drug delivery, bio-imaging and theranostics are also classified in this review. Finally, the remaining challenges and future perspectives for further development of unimolecular micelles as therapeutic materials are also discussed.

Synthesis of well-defined star, star-block, and miktoarm star biodegradable polymers based on PLLA and PCL by one-pot azide-alkyne click reaction

Based on the "arm-first" strategy, ring-opening polymerization (ROP) and one-pot azide-alkyne click reaction, well-defined star-shaped polymers with different architectures have been successfully synthesized, including the star homopolymers four-arm star-shaped polycaprolactone (4sPCL) and four-arm star-shaped poly(l-lactic acid) (4sPLLA), star-block copolymer 4sPCL-b-PLLA and miktoarm star-shaped copolymer PCL2PLLA2. The star homopolymers 4sPCL and 4sPLLA were synthesized by a click reaction of an azide small molecule initiator and HC[triple bond, length as m-dash]C-PCL or HC[triple bond, length as m-dash]C-PLLA. The star-block copolymer 4sPCL-b-PLLA was synthesized by a click reaction of an azide small molecule initiator and the block copolymer HC[triple bond, length as m-dash]C-PCL-b-PLLA. The miktoarm star polymer PCL2PLLA2 was synthesized by a one-pot azide-alkyne click reaction of simultaneous addition of equal proportions of HC[triple bond, length as m-dash]C-PCL and HC[triple bond, length as m-dash]C-PLLA. The structures of these star-shaped polymers have been confirmed by NMR, FT-IR and GPC. Furthermore, the melting and crystallization behaviors investigated using DSC and WXRD also confirm the formation of star-shaped polymers with different architectures.

Polymeric Janus Nanoparticles: Recent Advances in Synthetic Strategies, Materials Properties, and Applications

Polymeric Janus nanoparticles with two sides of incompatible chemistry have received increasing attention due to their tunable asymmetric structure and unique material characteristics. Recently, with the rapid progress in controlled polymerization combined with novel fabrication techniques, a large array of functional polymeric Janus particles are diversified with sophisticated architecture and applications. In this review, the most recently developed strategies for controlled synthesis of polymeric Janus nanoparticles with well-defined size and complex superstructures are summarized. In addition, the pros and cons of each approach in mediating the anisotropic shapes of polymeric Janus particles as well as their asymmetric spatial distribution of chemical compositions and functionalities are discussed and compared. Finally, these newly developed structural nanoparticles with specific shapes and surface functions orientated applications in different domains are also discussed, followed by the perspectives and challenges faced in the further advancement of polymeric Janus nanoparticles as high performance materials.