Drug-loaded pseudo-block copolymer micelles with a multi-armed star polymer as the micellar exterior

Cabazitaxel-Loaded Thermosensitive Hydrogel System for Suppressed Orthotopic Colorectal Cancer and Liver Metastasis

The treatment of colorectal cancer is always a major challenge in the field of cancer research. The number of estimated new cases of colorectal cancer worldwide in 2020 is 1 148 515, and the estimated number of deaths is 576 858, revealing that mortality accounted for approximately half of the disease incidence. The development of new drugs and strategies for colorectal cancer treatment is urgently needed. Thermosensitive injectable hydrogel PDLLA-PEG-PDLLA (PLEL) loaded with cabazitaxel (CTX) is used to explore its anti-tumor effect on mice with orthotopic colorectal cancer. CTX/PLEL is characterized by a solution state at room temperature and a hydrogel state at physiologic temperature. The excipients MPEG-PCL and PDLLA-PEG-PDLLA have good biocompatibility and biodegradability. The simple material synthesis and preparation process renders this system cost-effective and more conducive to clinical transformation. An orthotopic colorectal cancer model is established by transplantation subcutaneous tumors onto the cecum of mice. According to the results of experiments in vivo, CTX/PLEL significantly inhibits orthotopic colorectal cancer and liver metastasis in mice. The results indicate that CTX/PLEL nanoparticle preparations have high security and excellent anti-tumor effects, and have great application potential in colorectal cancer therapy.

Recent Advances in Nanoparticle Development for Drug Delivery: A Comprehensive Review of Polycaprolactone-Based Multi-Arm Architectures

Controlled drug delivery is a crucial area of study for improving the targeted availability of drugs; several polymer systems have been applied for the formulation of drug delivery vehicles, including linear amphiphilic block copolymers, but with some limitations manifested in their ability to form only nanoaggregates such as polymersomes or vesicles within a narrow range of hydrophobic/hydrophilic balance, which can be problematic. For this, multi-arm architecture has emerged as an efficient alternative that overcame these challenges, with many interesting advantages such as reducing critical micellar concentrations, producing smaller particles, allowing for various functional compositions, and ensuring prolonged and continuous drug release. This review focuses on examining the key variables that influence the customization of multi-arm architecture assemblies based on polycaprolactone and their impact on drug loading and delivery. Specifically, this study focuses on the investigation of the structure-property relationships in these formulations, including the thermal properties presented by this architecture. Furthermore, this work will emphasize the importance of the type of architecture, chain topology, self-assembly parameters, and comparison between multi-arm structures and linear counterparts in relation to their impact on their performance as nanocarriers. By understanding these relationships, more effective multi-arm polymers can be designed with appropriate characteristics for their intended applications.

Synthesis of Supramolecular A8 Bn Miktoarm Star Copolymers by Host-Guest Complexation

We report a new synthetic method to construct supramolecular A₈ B_n (n=1, 2, 4) miktoarm star copolymers by host-guest complexation between a resorcinarene-based coordination capsule possessing eight polystyrene chains and 4,4-diacetoxybiphenyl guest molecules that retain one, two or four polymethyl acrylate chains. The formation of the supramolecular A₈ B_n (n=1, 2, 4) miktoarm star copolymers was confirmed by dynamic light scattering (DLS), size-exclusion chromatography (SEC), and diffusion-ordered NMR spectroscopy (DOSY). Differential scanning calorimetry (DSC) measurements revealed that the miktoarm copolymers were phase-separated in the bulk. The micro-Brownian motion of the A₈ B₄ structure was markedly enhanced in the bulk due to a weak segregation interaction between the immiscible arms.

Current development of cabazitaxel drug delivery systems

The second-generation taxane cabazitaxel has been clinically approved for the treatment of metastatic castration-resistant prostate cancer after docetaxel failure. Compared with the first-generation taxanes paclitaxel and docetaxel, cabazitaxel has potent anticancer activity and is less prone to drug resistance due to its lower affinity for the P-gp efflux pump. The relatively high hydrophobicity of cabazitaxel and the poor aqueous colloidal stability of the commercial formulation, following its preparation for injection, presents opportunities for new cabazitaxel formulations with improved features. This review provides an overview of cabazitaxel drug formulations and hydrophobic taxane drug delivery systems in general, and particularly focuses on emerging cabazitaxel delivery systems discovered in the past 5 years. This article is categorized under: Therapeutic Approaches and Drug Discovery > Nanomedicine for Oncologic Disease Therapeutic Approaches and Drug Discovery > Emerging Technologies.

Negatively charged polymer-shielded supramolecular nano-micelles with stimuli-responsive property for anticancer drug delivery

A new kind of negatively charged polymer-shielded supramolecular nano-micelles with dual-responsive property was designed for tumor treatment, which was prepared on the basis of adamantane terminated linear PAsp(DIP) and disulfide-β-cyclodextrin-terminated PAsp(EDA). The supramolecular nano-micelles comprised a 2,3-dimethylmaleic anhydride (DA) protective layer to stabilize the micelles, a pH-responsive core to package hydrophobic model drugs, and a disulfide-crosslinked interlayer to shackle the core against drug leakage under normal physiological conditions. After arriving at the tumor tissue via EPR, the targeting function could be turned on by dislodging DA groups on the surface of micelles, which allowed the drug-loaded nano-micelles to be easily phagocytized by the tumor cells, and then release the drug inside the cells induced by the increased glutathione level and acidic pH. The results indicated that the charge-conversional dual-responsive supramolecular nano-micelles showed excellent antitumor activity.

Emerging nanotechnology based combination therapies of taxanes for multiple drug-resistant cancers

'One drug- one target' to 'multiple drug- multiple targets' paradigm shifted to produce combination therapies, have found great outcomes to overcome multiple drug resistance (MDR). MDR is a significant barrier to the delivery of taxane-based anticancer medicines such as docetaxel, paclitaxel, and cabazitaxel. Due to MDR induced by drug efflux transporters, clinical application of these medications is impeded. To date, nanoformulations such as liposomes, micelles, polymeric nanoparticles, and gold nanoparticles have been investigated to deliver taxanes alone and in combination to reverse drug resistance. Despite the fact that various groups have already looked into taxane nano formulations in the literature, there isn't much in the way of polypharmacology and advanced nanoformulations with a focus on MDR. In this overview, we briefly covered the insights regarding MDR, difficulties related to current pharmaceutical products of taxanes, combination therapies of taxanes to combat MDR, all of which can be used to delve into cancer treatment.

Biodegradable supramolecular micelles via host-guest interaction of cyclodextrin-terminated polypeptides and adamantane-terminated polycaprolactones

Biodegradable supramolecular micelles were prepared exploiting the host-guest interaction of cyclodextrin and adamantane. Cyclodextrin-initiated polypeptides acted as the hydrophilic corona, whereas adamantane-terminated polycaprolactones served as the hydrophobic core.

Recent progress in nanoformulations of cabazitaxel

The antitumor efficacy of various paclitaxel (PTX) and docetaxel (DTX) formulations in clinical applications is seriously affected by drug resistance. Cabazitaxel, a second-generation taxane, exhibits greater anticancer activity than paclitaxel and docetaxel and has low affinity for the P-glycoprotein (P-gp) efflux pump because of its structure. Therefore, cabazitaxel has the potential to overcome taxane resistance. However, owing to the high systemic toxicity and hydrophobicity of cabazitaxel and the instability of its commercial preparation, Jevtana®, the clinical use of cabazitaxel is restricted to patients with metastatic castration-resistant prostate cancer (mCRPC) who show progression after docetaxel-based chemotherapy. Nanomedicine is expected to overcome the limitations associated with cabazitaxel application and surmount taxane resistance. This review outlines the drug delivery systems of cabazitaxel published in recent years, summarizes the challenges faced in the development of cabazitaxel nanoformulations, and proposes strategies to overcome these challenges.

The classification and application of cyclodextrin polymers: a review

After introducing the concept of cyclodextrin polymers, their classification and applications have been summarized.

Synthesis and Electrospinning of Polycaprolactone from an Aluminium-Based Catalyst: Influence of the Ancillary Ligand and Initiators on Catalytic Efficiency and Fibre Structure

In the present study, we investigated the catalytic performance of a 2,2'-methylenebis(6-tert-butyl-4-methylphenol) (MDBP)⁻aluminium complex for the ring-opening polymerisation (ROP) of ε-caprolactone in combination with various alcohols as initiators. Three different alcohols were investigated: 1-adamantanemethanol (A), 1H,1H,2H,2H-perfluoro-1-octanol (F) and isopropanol (I). Samplings of polycaprolactone (PCL) at various reaction times showed a linear increase in the polymer molecular weight with time, with very narrow polydispersity, confirming the living nature of the catalytic system. Scanning electron microscope (SEM) images of electrospun PCL fibre mats produced from 30 wt % dichloromethane/dimethyl sulfoxide solutions showed a high level of surface porosity with a reasonable homogeneity of fibre diameters. The values of the liquid absorption and water contact angle were measured for the electrospun mats, with the F-capped PCL consistently showing absorption values up to three times higher than those of PCL samples capped with the other two alcohols, as well as increased hydrophobicity. The nature of the alcohol can influence the surface hydrophobicity and absorption ability of electrospun fibres, demonstrating the possibility of tailoring material properties through controlled polymerisation.

Translatable High Drug Loading Drug Delivery Systems Based on Biocompatible Polymer Nanocarriers

Most nanocarriers possess low drug loading, resulting in frequently repeated administration and thereby high cost and increased side effects. Furthermore, the characteristics of nanocarrier materials, especially the drug loading capacity, plays a vital role in the drug delivery efficacy. In this review, we focus on the readily translatable polymeric drug delivery systems with high drug loading, which are comprised of biocompatible polymers such as poly(ethylene glycol), poly( N-vinylpyrrolidone), polyoxazoline, natural proteins like albumin and casein, non-natural proteins such as recombinant elastin-like polypeptides, as well as nucleic acids. At the end of this review, applications of these polymeric nanocarriers on the delivery of proteins and gene drugs are also briefly discussed.

Programmed photosensitizer conjugated supramolecular nanocarriers with dual targeting ability for enhanced photodynamic therapy

A programmed supramolecular nanocarrier was developed for multistage targeted photodynamic therapy. This smart nanocarrier exhibited enhanced cellular uptake and controlled mitochondria targeting, as well as an excellent photodynamic therapeutic effect after light irradiation.

Dendritic phospholipid-based drug delivery systems

A class of new dendritic phospholipid compounds with different hydrophilic dendritic poly(l-lysine) peripheries from generations 1 (G1) to 3 (G3) (DPL-1 to DPL-3) were synthesised and nano-drug delivery systems based on these compounds were prepared (DPN-2 and DPN-3).

Dual-responsive recurrent self-assembly of a supramolecular polymer based on the host–guest complexation interaction between β-cyclodextrin and azobenzene

A novel supramolecular polymer PAE-g-Azo@β-CD-PEG was constructed, which significantly displayed pH- and photo-dual-responsive recurrent self-assembly behaviors.

Versatile Functionalization of Polysaccharides via Polymer Grafts: From Design to Biomedical Applications

Because of their biocompatibility, biodegradability, and unique bioactive properties, polysaccharides have been recognized and directly applied as excellent candidates for various biomedical applications. In order to introduce more functionalities onto polysaccharides, various modification methods were applied to improve the physical-chemical and biochemical properties. Grafting polysaccharides with functional polymers with limited reaction sites maximizes the structural integrity. To the best of our knowledge, great efforts have been made by scientists across the world, including our research group, to explore different strategies for the synthesis and design of controllable polymer-grafted polysaccharides. By the application of some reasonable strategies, a series of polymer-grafted polysaccharides with satisfactory biocharacteristics were obtained. The first strategy involves facile modification of polysaccharides with living radical polymerization (LRP). Functionalized polysaccharides with diverse grafts can be flexibly and effectively achieved. The introduced grafts include cationic components for nuclei acid delivery, PEGylated and zwitterionic moieties for shielding effects, and functional species for bioimaging applications as well as bioresponsive drug release applications. The second synthetic model refers to biodegradable polymer-grafted polysaccharides prepared by ring-opening polymerization (ROP). Inspired by pathways to introduce initiation sites onto polysaccharides, the use of amine-functionalized polysaccharides was explored in-depth to trigger ROP of amino acids. A series of poly(amino acid)-grafted polysaccharides with advanced structures (including linear, star-shaped, and comb-shaped copolymers) were developed to study and optimize the structural effects. In addition, biodegradable polyester-grafted polysaccharides were prepared and utilized for drug delivery. Another emerging strategy was to design polysaccharide-based assemblies with supramolecular structures. A variety of assembly techniques using non-covalent interactions were established to construct different types of polysaccharide-based assemblies with various bioapplications. On the basis of these strategies, polymer-grafted polysaccharides with controllable functions were reported to be well-suited for different kinds of biomedical applications. The exciting results were obtained from both in vitro and in vivo models. Viewing the rapid growth of this field, the present Account will update the concepts, trends, perspectives, and applications of functionalized polysaccharides, guiding and inspiring researchers to explore new polysaccharide-based systems for wider applications.

Star-Shaped Copolymers Based on Poly(N-vinylcaprolactam) and their Use as Nanocarriers of Methotrexate

Star-shaped poly(N-vinylcaprolactam)-block-poly(ethylhexylacrylate)-block-polyethylene glycol (PNVCL-b-PEHA-b-PEG) triblock copolymers and star-shaped poly(N-vinylcaprolactam)-block-polyethylene glycol (PNVCL-b-PEG) diblock copolymers were synthesized by reversible addition–fragmentation chain transfer (RAFT) polymerization. The resulting star block copolymers were characterized using 1H NMR and UV-vis spectroscopy, gel permeation chromatography, and dynamic light scattering. The star-shaped PNVCL-b-PEG and PNVCL-b-PEHA-b-PEG block copolymers self-assemble spontaneously into aggregates in water. The aggregates formed ranged from ~17 to 135 nm in diameter and were used to encapsulate methotrexate (MTX). It was observed that the aggregates from PNVCL-b-PEHA-b-PEG copolymers exhibited a higher drug loading and a lower release of MTX (19 wt-% and 54 %) as compared with star copolymers without PEHA (5 wt-% and 81 %) after 24 h at a temperature below their lower critical solution temperature values.

Design and construction of self-hidden and pH-reversed targeting drug delivery nanovehicles via noncovalent interactions to overcome drug resistance

A convenient one-step method was used to construct self-hidden and pH-reversed targeting drug delivery nanovehicles using the host–guest interaction between β-CD and Ad, and borate formation between PBA and serinol.

Multicellular tumor spheroids: a relevant 3D model for the in vitro preclinical investigation of polymer nanomedicines

Application of 3D multicellular tumor spheroids to the investigation of polymer nanomedicines.

Redox-Activated Light-Up Nanomicelle for Precise Imaging-Guided Cancer Therapy and Real-Time Pharmacokinetic Monitoring

Simultaneous tumor imaging, therapy, and pharmacokinetic monitoring can offer a safe and effective strategy for cancer therapy. This work describes the design of a fluorescence light-up nanomicelle that can afford precise imaging-guided drug delivery and pharmacokinetic monitoring in a real-time fashion for cancer chemotherapy. The nanomicelle, which contains a boron dipyrromethene based fluorescent probe as the hydrophobic core and a redox-triggered detachable poly(ethylene glycol) (PEG) shell, can accumulate at the tumor site via enhanced permeation and retention effect. The PEG detachment induced by tumoral and intracellular glutathione can destabilize the nanomicelle, leading to fluorescence light up and simultaneous drug release. Importantly, the fluorescence intensities generated by the nanomicelles in different organs are well-correlated with released drug concentrations in both temporal and spatial manners, suggesting its precise role for imaging-guided drug delivery and pharmacokinetic monitoring in vivo. The tumor growth can be effectively inhibited by the docetaxel-loaded nanomicelle formulation, and the nanomicelles are monitored to be excreted via hepatobiliary routes. This nanomicelle for precise imaging-guided chemotherapy provides a safe and robust theranostic strategy for the evaluation of cancer nanomedicine.