Phenylboronic acid-sugar grafted polymer architecture as a dual stimuli-responsive gene carrier for targeted anti-angiogenic tumor therapy

A glycopolymersome strategy for 'drug-free' treatment of diabetic nephropathy

Diabetic nephropathy is a severe complication of diabetes. Treatment of diabetic nephropathy is an important challenge due to persistent hyperglycemia and elevated levels of reactive oxygen species (ROS) in the kidney. Herein, we designed a glycopolymersome that can treat type 2 diabetic nephropathy by effectively inhibiting hyperglycemia and ROS-associated diabetic nephropathy pathogenesis. The glycopolymersome is self-assembled from phenylboronic acid derivative-containing copolymer, poly(ethylene oxide)45-block-poly[(aspartic acid)13-stat-glucosamine24-stat-(phenylboronic acid)18-stat-(phenylboronic acid pinacol ester)3] [PEO45-b-P(Asp13-stat-GA24-stat-PBA18-stat-PAPE3)]. PBA segment can reversibly bind blood glucose or GA segment for long-term regulation of blood glucose levels; PAPE segment can scavenge excessive ROS for renoprotection. In vitro studies confirmed that the glycopolymersomes exhibit efficient blood glucose responsiveness within 2 h and satisfactory ROS-scavenging ability with 500 μM H2O2. Moreover, the glycopolymersomes display long-acting regulation of blood glucose levels in type 2 diabetic nephropathy mice within 32 h. Dihydroethidium staining revealed that these glycopolymersomes reduced ROS to normal levels in the kidney, which led to 61.7% and 76.6% reduction in creatinine and urea levels, respectively, along with suppressing renal apoptosis, collagen accumulation, and glycogen deposition in type 2 diabetic nephropathy mice. Notably, the polypeptide-based glycopolymersome was synthesized by ring-opening polymerization (ROP) of N-carboxyanhydrides (NCAs), thereby exhibiting favorable biodegradability. Overall, we proposed a new glycopolymersome strategy for 'drug-free' treatment of diabetic nephropathy, which could be extended to encompass the design of various multifunctional nanoparticles targeting diabetes and its associated complications.

Smart Nanoplatforms Responding to the Tumor Microenvironment for Precise Drug Delivery in Cancer Therapy

The tumor microenvironment (TME) is a complex and dynamic entity, comprising stromal cells, immune cells, blood vessels and extracellular matrix, which is intimately associated with the occurrence and development of cancers, as well as their therapy. Utilizing the shared characteristics of tumors, such as an acidic environment, enzymes and hypoxia, researchers have developed a promising cancer therapy strategy known as responsive release of nano-loaded drugs, specifically targeted at tumor tissues or cells. In this comprehensive review, we provide an in-depth overview of the current fundamentals and state-of-the-art intelligent strategies of TME-responsive nanoplatforms, which include acidic pH, high GSH levels, high-level adenosine triphosphate, overexpressed enzymes, hypoxia and reductive environment. Additionally, we showcase the latest advancements in TME-responsive nanoparticles. In conclusion, we thoroughly examine the immediate challenges and prospects of TME-responsive nanopharmaceuticals, with the expectation that the progress of these targeted nanoformulations will enable the exploitation, overcoming or modulation of the TME, ultimately leading to significantly more effective cancer therapy.

Structural and Property Characterizations of Dual-Responsive Core-Shell Tecto Dendrimers for Tumor Penetration and Gene Delivery Applications

Core-shell tecto dendrimers (CSTDs) with excellent physicochemical properties and good tumor penetration and gene transfection efficiency have been demonstrated to have the potential to replace high-generation dendrimers in biomedical applications. However, their characterization and related biological properties of CSTDs for enhanced tumor penetration and gene delivery still lack in-depth investigation. Herein, three types of dual-responsive CSTDs are designed for thorough physicochemical characterization and investigation of their tumor penetration and gene delivery efficiency. Three types of CSTDs are prepared through phenylborate ester bonds of phenylboronic acid (PBA)-decorated generation 5 (G5) poly(amidoamine) (PAMAM) dendrimers as cores and monose (galactose, glucose, or mannose)-conjugated G3 PAMAM dendrimers as shells and thoroughly characterized via NMR and other techniques. It is shown that the produced CSTDs display strong correlation signals between the PBA and monose protons, similar hydrodynamic diameters, and dual reactive oxygen species- and pH-responsivenesses. The dual-responsive CSTDs are proven to have structure-dependent tumor penetration property and gene delivery efficiency in terms of small interference RNA for gene silencing and plasmid DNA for gene editing, thus revealing a great potential for different biomedical applications.

Dual-drug delivery by thermo-responsive Janus nanogel for improved cellular uptake, sustained release, and combination chemo-thermal therapy

The goal of this work was to examine the heat-sensitizing effects of Janus-coated magnetic nanoparticles (JMNPs) as a vehicle for 5-fluorouracil (5-Fu) and Quercetin (Qu) in C6 and OLN-93 cell lines. The cellular uptake of nanoparticles was evaluated using Prussian blue staining and ICP-OES after monolayer culturing of C6 (rat brain cancer cell) and OLN-93 (normal rat brain cell) cells. The cells were treated with free 5-Fu, Qu, and MJNPs loaded with Qu/5-Fu for 24 h, followed by magnetic hyperthermia under an alternating magnetic field (AMF) at a temperature of 43 °C. Using the MTT test and Flow cytometry, the C6 and OLN-93 cells were investigated after being subjected to hyperthermia with and without magnetic nanoparticles. The results of Prussian blue staining confirmed the potential of MJNPs as carriers that facilitate the uptake of drugs by cancer cells. The results showed that the combined application of Qu/5-Fu/MJNPs with hyperthermia significantly increased the amount of ROS production compared to interventions without MJNPs. The therapeutic results demonstrated that the combination of Qu/5-Fu/MJNPs with hyperthermia considerably enhanced the rate of apoptotic and necrotic cell death compared to that of interventions without MJNPs. Furthermore, MTT findings indicated that controlled exposure of Qu/5-Fu/MJNPs to AMF caused a synergistic effect. The advanced Janus magnetic nanoparticles in this study can be proposed as a promising dual drug carrier (Qu/5-Fu) and thermosensitizer platform for dual-modal synergistic cancer therapy.

Redox-Responsive Polymeric Nanoparticle for Nucleic Acid Delivery and Cancer Therapy: Progress, Opportunities, and Challenges

Cancer development and progression of cancer are closely associated with the activation of oncogenes and loss of tumor suppressor genes. Nucleic acid drugs (e.g., siRNA, mRNA, and DNA) are widely used for cancer therapy due to their specific ability to regulate the expression of any cancer-associated genes. However, nucleic acid drugs are negatively charged biomacromolecules that are susceptible to serum nucleases and cannot cross cell membrane. Therefore, specific delivery tools are required to facilitate the intracellular delivery of nucleic acid drugs. In the past few decades, a variety of nanoparticles (NPs) are designed and developed for nucleic acid delivery and cancer therapy. In particular, the polymeric NPs in response to the abnormal redox status in cancer cells have garnered much more attention as their potential in redox-triggered nanostructure dissociation and rapid intracellular release of nucleic acid drugs. In this review, the important genes or signaling pathways regulating the abnormal redox status in cancer cells are briefly introduced and the recent development of redox-responsive NPs for nucleic acid delivery and cancer therapy is systemically summarized. The future development of NPs-mediated nucleic acid delivery and their challenges in clinical translation are also discussed.

Advancing cell surface modification in mammalian cells with synthetic molecules

Biological cells, being the fundamental entities of life, are widely acknowledged as intricate living machines. The manipulation of cell surfaces has emerged as a progressively significant domain of investigation and advancement in recent times. Particularly, the alteration of cell surfaces using meticulously crafted and thoroughly characterized synthesized molecules has proven to be an efficacious means of introducing innovative functionalities or manipulating cells. Within this realm, a diverse array of elegant and robust strategies have been recently devised, including the bioorthogonal strategy, which enables selective modification. This review offers a comprehensive survey of recent advancements in the modification of mammalian cell surfaces through the use of synthetic molecules. It explores a range of strategies, encompassing chemical covalent modifications, physical alterations, and bioorthogonal approaches. The review concludes by addressing the present challenges and potential future opportunities in this rapidly expanding field.

Dual-Cross-Linked PEI/PVA Hydrogel for pH-Responsive Drug Delivery

Herein, a pH-responsive dual cross-linked hydrogel for controlled drug release is presented. The hydrogel was constructed with reversible borate ester bonds and crystalline poly(vinyl alcohol). By changing the environmental pH, its physicochemical characteristics, including rheological properties, mechanical properties, microstructural features, and the biocompatibility of the gels, were evaluated. The gels at tumor acidic conditions exhibited swelling and lower compressive strength and modulus than those in a physiological environment, which was attributed to the pH-responsive borate ester bonds and the protonation of amine groups on the PEI polyelectrolyte. Importantly, the drug-encapsulated biocompatible hydrogel showed sustained and increased release under an acidic environment, and it followed the Fickian diffusion mechanism. Therefore, it exemplifies that borate ester bond-based pH-responsive biomaterials have high promise in biomedical research, especially for drug delivery.

A Trojan Horse Delivery Vehicle Carrying siRNA Nanotherapeutics with Multiple Tumor Microenvironment Responsiveness Elicits Robust Antitumor Immune Responses In Situ via a "Self-Synergistic" Approach

The potential of small interfering RNAs (siRNAs) in the treatment of malignant tumors has attracted increasing attention due to their inherent advantages. However, their therapeutic performance strongly depends on the efficiency of their cytoplasmic delivery in vivo by the delivery vehicle with good cellular permeability and histocompatibility. Herein, a polycationic carrier camouflaged with macrophage membrane (MPM) is constructed biomimetically, which is condensed from endogenous spermine monomers through diselenide bonds. The developed Trojan horse delivery vehicle has desirable compression efficacy for siRNA oligo against PD-L1 (siPDL1) as well as intracytoplasmic release properties derived from its sequential degradation triggered by redox microenvironment in tumor cells. Furthermore, the coloading of photosensitizer can mediate photodynamic therapy (PDT) accompanied by the generation of reactive oxygen species (ROS) upon light irradiation applied, which accelerated the degradation of the carrier as well as the release of cargoes while enhancing the PD-L1 blockage-mediated immunotherapy by inducing in-situ immunogenic cell death. Moreover, the synchronously delivered siPDL1 attenuated the ROS-induced increase in immunosuppressive PD-L1 expression, thereby effectively eliciting a robust antitumor immune response with a "self-synergistic" manner in the xenograft breast cancer mouse model.

Emerging nanotechnological approaches to regulating tumor vasculature for cancer therapy

Abnormal angiogenesis stands for one of the most striking manifestations of malignant tumor. The pathologically and structurally abnormal tumor vasculature facilitates a hostile tumor microenvironment, providing an ideal refuge exclusively for cancer cells. The emergence of vascular regulation drugs has introduced a distinctive class of therapeutics capable of influencing nutrition supply and drug delivery efficacy without the need to penetrate a series of physical barriers to reach tumor cells. Nanomedicines have been further developed for more precise regulation of tumor vasculature with the capacity of co-delivering multiple active pharmaceutical ingredients, which overall reduces the systemic toxicity and boosts the therapeutic efficacy of free drugs. Additionally, precise structure design enables the integration of specific functional motifs, such as surface-targeting ligands, droppable shells, degradable framework, or stimuli-responsive components into nanomedicines, which can improve tissue-specific accumulation, enhance tissue penetration, and realize the controlled and stimulus-triggered release of the loaded cargo. This review describes the morphological and functional characteristics of tumor blood vessels and summarizes the pivotal molecular targets commonly used in nanomedicine design, and then highlights the recent cutting-edge advancements utilizing nanotechnologies for precise regulation of tumor vasculature. Finally, the challenges and future directions of this field are discussed.

Polymeric biomaterial-inspired cell surface modulation for the development of novel anticancer therapeutics

Immune cell-based therapies are a rapidly emerging class of new medicines that directly treat and prevent targeted cancer. However multiple biological barriers impede the activity of live immune cells, and therefore necessitate the use of surface-modified immune cells for cancer prevention. Synthetic and/or natural biomaterials represent the leading approach for immune cell surface modulation. Different types of biomaterials can be applied to cell surface membranes through hydrophobic insertion, layer-by-layer attachment, and covalent conjugations to acquire surface modification in mammalian cells. These biomaterials generate reciprocity to enable cell-cell interactions. In this review, we highlight the different biomaterials (lipidic and polymeric)-based advanced applications for cell-surface modulation, a few cell recognition moieties, and how their interplay in cell-cell interaction. We discuss the cancer-killing efficacy of NK cells, followed by their surface engineering for cancer treatment. Ultimately, this review connects biomaterials and biologically active NK cells that play key roles in cancer immunotherapy applications.

Dual-Responsive Core-Shell Tecto Dendrimers Enable Efficient Gene Editing of Cancer Cells to Boost Immune Checkpoint Blockade Therapy

Immune checkpoint blockade (ICB) therapy has become a promising strategy in treating multiple tumor types, but the therapeutic efficacy is still unsatisfactory due to the temporary and inefficient blocking and the poor immune responsiveness. Herein, we report the development of dual reactive oxygen species (ROS)- and pH-responsive core-shell tecto dendrimers loaded with gold nanoparticles (for short, Au CSTDs) to deliver a plasmid-clustered regularly interspersed short palindromic repeats (CRISPR)/Cas9 system for the permanent disruption of the programmed death ligand 1 (PD-L1) gene in cancer cells to boost cancer immunotherapy. In our work, Au CSTDs were constructed using lactobionic acid (LA)-modified generation 5 poly(amidoamine) dendrimers entrapped with gold nanoparticles as cores and phenylboronic acid (PBA)-conjugated generation 3 dendrimers as shells via the formation of responsive phenylborate ester bonds between PBA and LA. The plasmid-CRISPR/Cas9 system can be efficiently compacted and specifically taken up by cancer cells overexpressing sialic acids due to the PBA-mediated targeting and be responsively released in cancer cells by the responsive dissociation of the Au CSTDs, leading to the successful endosomal escape and the efficient knockout of the PD-L1 gene. Further in vivo delivery in a mouse melanoma model reveals that the developed Au CSTDs/plasmid-CRISPR/Cas9 complexes can be specifically accumulated at the tumor site for enhanced computed tomography (CT) imaging of tumors, owing to the X-ray attenuation effect of Au, and disrupt the PD-L1 expression in tumor cells, thus promoting the ICB-based antitumor immunity. The designed dual-responsive Au CSTDs may be developed as a versatile tool for genetic engineering of other cell types to achieve different therapeutic effects for expanded space of biomedical applications.

Tumor-Targeting Nanoassembly for Enhanced Colorectal Cancer Therapy by Eliminating Intratumoral Fusobacterium nucleatum

Fusobacterium nucleatum (Fn) has long been found to be related to colorectal cancer (CRC), which could promote colorectal tumor progression and cause cancer resistance to chemotherapy. Great efforts have been made to understand the relationship between Fn and CRC, but how to efficiently eliminate intratumoral Fn and overcome chemoresistance remains a critical challenge. Here, an active tumor-targeting acidity-responsive nanomaterial toward eliminating intratumoral Fn is developed for enhancing the treatment of cancer. Lauric acid and phenylboric acid are conjugated to oligomethyleneimine to form OLP followed by interacting with oxaliplatin prodrug-modified polyglycidyl ether (PP) to obtain the OLP/PP nanoassembly. The nanoassembly shows good structural stability under the simulated physiological conditions and has a pH-responsive drug release in an acidic tumor microenvironment. More attractively, the nanoassembly can specifically target the tumor cell, guide cellular uptake, and efficiently eliminate tumor-resident extracellular and intracellular Fn. Through the on-site drug delivery, the nanoassembly can overcome chemoresistance and significantly inhibit tumor growth. Both in vitro and vivo studies show that the prepared nanoassembly presents good biocompatibility. Therefore, this biocompatible nanoassembly possessing efficient antibacterial and antitumor activities provides new promise for the therapy of bacterial infected tumors.

Tailoring biomimetic dual-redox-responsive nanoplexes for enhanced RNAi-synergized photodynamic cancer immunotherapy

Despite the strong potential of RNA interference (RNAi) therapies, critical issues, such as poor permeability across biological membranes and efficacy of their delivery into the cytoplasm, remain to be addressed before their successful clinical application. The current study aimed to address these issues by constructing a biomimetic nanoplex with dual redox responsiveness, which is derived from a cationic polymer formed by the condensation of endogenous spermine monomers via diselenide bonds. The developed nanoplexes decomposed in response to the redox microenvironment in cancer cells, thereby avoiding accumulation toxicity and poor transfection efficiency owing to incomplete siRNA release. When co-delivered with siPDL1 and a photosensitizer, the reactive oxygen species generated by irradiated nanoplexes accelerated the cytoplasmic release of siPDL1, which was expected to alleviate the PDT-induced increase in immunosuppressive PD-L1 expression. In a murine model of 4T1 xenografted breast cancer, the fabricated macrophage membrane (MPM)-camouflaged nanoplexes with payloads boosted antitumor immune responses in situ through a "self-synergistic" immunogenic cell death induced by photodynamic therapy (PDT). Overall, the study reported a new strategy for harnessing photodynamic immunotherapy for treating immunologically cold tumors. STATEMENT OF SIGNIFICANCE: This study provides a biomimetic nanoplex with dual redox responsiveness, which is derived from a novel cationic polymer formed by the condensation of endogenous spermine monomers through diselenide bonds. The developed nanoplex disassembles according to the redox microenvironment in cancer cells, thereby avoiding accumulation toxicity and poor transfection efficiency due to incomplete siRNA release. When co-delivery of siPDL1 and photosensitizer in vivo, the ROS generated by irradiated nanoplexes accelerated the cytoplasmic release of siPDL1, and which is expected to alleviate PDT-induced increase in immunosuppressive PD-L1 expression, thereby boosting antitumor immune responses in situ through a "self-synergistic" immunogenic cell death induced by PDT. Our findings reveal a new strategy of harnessing photodynamic immunotherapy therapy toward immunologically cold tumors.

Phenylboronic Acid-Functionalized Polyplexes Tailored to Oral CRISPR Delivery

Effective delivery of the CRISPR-Cas9 components is crucial to realizing the therapeutic potential. Although many delivery approaches have been developed for this application, oral delivery has not been explored due to the degradative nature of the gastrointestinal tract. For this issue, we developed a series of novel phenylboronic acid (PBA)-functionalized chitosan-polyethylenimine (CS-PEI) polymers for oral CRISPR delivery. PBA functionalization equipped the polyplex with higher stability, smooth transport across the mucus, and efficient endosomal escape and cytosolic unpackaging in the cells. From a library of 12 PBA-functionalized CS-PEI polyplexes, we identified a formulation that showed the most effective penetration in the intestinal mucosa after oral gavage to mice. The optimized formulation performed feasible CRISPR-mediated downregulation of the target protein and reduction in the downstream cholesterol. As the first oral CRISPR carrier, this study suggests the potential of addressing the needs of both local and systemic editing in a patient-compliant manner.

High-Performance Delivery of a CRISPR Interference System via Lipid-Polymer Hybrid Nanoparticles Combined with Ultrasound-Mediated Microbubble Destruction for Tumor-Specific Gene Repression

The dCas9-based CRISPR interference (CRISPRi) system efficiently silences genes without causing detectable off-target activity, thus showing great potential for the treatment of cancer at the transcriptional level. However, due to the large size of the commonly used CRISPRi system, effective delivery of the system has been a challenge that hinders its application in the clinic. Herein, a combination of pH-responsive lipid-polymer hybrid nanoparticles (PLPNs) and ultrasound-mediated microbubble destruction (UMMD) is used for the delivery of the CRISPRi system. The core-shell structure of PLPNs can effectively be loaded with the CRISPRi plasmid, and increases the time spent in the circulating in vivo, and "actively target" cancer cells. Moreover, the combination of PLPNs with UMMD achieves a higher cellular uptake of the CRISPRi plasmid in vitro and retention in vivo. Furthermore, when PLPNs loaded with a CRISPRi plasmid that targets microRNA-10b (miR-10b) are used in combination with UMMD, it results in the effective repression of miR-10b in breast cancer, simultaneous disturbance of multiple cell migration and invasion-related signaling pathways, and a significant inhibition of lung metastasis. Thus, the established system presents a versatile, highly efficient, and safe strategy for delivery of the CRISPRi system both in vitro and in vivo.

Nanotechnology in cervical cancer immunotherapy: Therapeutic vaccines and adoptive cell therapy

Immunotherapy is an emerging method for the treatment of cervical cancer and is more effective than surgery and radiotherapy, especially for recurrent cervical cancer. However, immunotherapy is limited by adverse effects in clinical practice. In recent years, nanotechnology has been widely used for tumor diagnosis, drug delivery, and targeted therapy. In the setting of cervical cancer, nanotechnology can be used to actively or passively target immunotherapeutic agents to tumor sites, thereby enhancing local drug delivery, reducing drug adverse effects, achieving immunomodulation, improving the tumor immune microenvironment, and optimizing treatment efficacy. In this review, we highlight the current status of therapeutic vaccines and adoptive cell therapy in cervical cancer immunotherapy, as well as the application of lipid carriers, polymeric nanoparticles, inorganic nanoparticles, and exosomes in this context.

Microgel-Assisted Delivery of Adenosine to Accelerate Fracture Healing

Extracellular adenosine plays a key role in promoting bone tissue formation. Local delivery of adenosine could be an effective therapeutic strategy to harness the beneficial effect of extracellular adenosine on bone tissue formation following injury. Herein, we describe the development of an injectable in situ curing scaffold containing microgel-based adenosine delivery units. The two-component scaffold includes adenosine-loaded microgels and functionalized hyaluronic acid (HA) molecules. The microgels were generated upon copolymerization of 3-acrylamidophenylboronic acid (3-APBA)- and 2-aminoethylmethacrylamide (2-AEMA)-conjugated HA (HA-AEMA) in an emulsion suspension. The PBA functional groups were used to load the adenosine molecules. Mixing of the microgels with the HA polymers containing clickable groups, dibenzocyclooctyne (DBCO) and azide (HA-DBCO and HA-Azide), resulted in a 3D scaffold embedded with adenosine delivery units. Application of the in situ curing scaffolds containing adenosine-loaded microgels following tibial fracture injury showed improved bone tissue healing in a mouse model as demonstrated by the reduced callus size, higher bone volume, and increased tissue mineral density compared to those treated with the scaffold without adenosine. Overall, our results suggest that local delivery of adenosine could potentially be an effective strategy to promote bone tissue repair.

Bridging mRNA and Polycation Using RNA Oligonucleotide Derivatives Improves the Robustness of Polyplex Micelles for Efficient mRNA Delivery

Polyplex for messenger RNA (mRNA) delivery requires strong yet reversible association between mRNA and polycation for extracellular robustness and selective intracellular disintegration. Herein, RNA oligonucleotide (OligoRNA) derivatives that bridge mRNA and polycation are developed to stabilize polyplex micelles (PMs). A set of the OligoRNAs introduced with a polyol moiety in their 5' end is designed to hybridize to fixed positions along mRNA strand. After PM preparation from the hybridized mRNA and poly(ethylene glycol)-polycation block copolymer derived with phenylboronic acid (PBA) moieties in its cationic segment, PBA moieties form reversible phenylboronate ester linkages with a polyol moiety at 5' end of OligoRNAs and a diol moiety at their 3' end ribose, in the PM core. The OligoRNAs work as a node to bridge ionically complexed mRNA and polycation, thereby improving PM stability against polyion exchange reaction and ribonuclease attack in extracellular environment. After cellular uptake, intracellular high concentration of adenosine triphosphate triggers the cleavage of phenylboronate ester linkages, resulting in mRNA release from PM. Ultimately, the PM provides efficient mRNA introduction in cultured cells and mouse lungs after intratracheal administration, demonstrating the potential of the bridging strategy in polyplex-based mRNA delivery.

Rational Designs at the Forefront of Mitochondria-Targeted Gene Delivery: Recent Progress and Future Perspectives

Mitochondria play an essential role in cellular metabolism and generate energy in cells. To support these functions, several proteins are encoded in the mitochondrial DNA (mtDNA). The mutation of mtDNA causes mitochondrial dysfunction and ultimately results in a variety of inherited diseases. To date, gene delivery systems targeting mitochondria have been developed to ameliorate mtDNA mutations. However, applications of these strategies in mitochondrial gene therapy are still being explored and optimized. Thus, from this perspective, we herein highlight recent mitochondria-targeting strategies for gene therapy and discuss future directions for effective mitochondria-targeted gene delivery.

Charge reversal nano-systems for tumor therapy

Surface charge of biological and medical nanocarriers has been demonstrated to play an important role in cellular uptake. Owing to the unique physicochemical properties, charge-reversal delivery strategy has rapidly developed as a promising approach for drug delivery application, especially for cancer treatment. Charge-reversal nanocarriers are neutral/negatively charged at physiological conditions while could be triggered to positively charged by specific stimuli (i.e., pH, redox, ROS, enzyme, light or temperature) to achieve the prolonged blood circulation and enhanced tumor cellular uptake, thus to potentiate the antitumor effects of delivered therapeutic agents. In this review, we comprehensively summarized the recent advances of charge-reversal nanocarriers, including: (i) the effect of surface charge on cellular uptake; (ii) charge-conversion mechanisms responding to several specific stimuli; (iii) relation between the chemical structure and charge reversal activity; and (iv) polymeric materials that are commonly applied in the charge-reversal delivery systems.

Potential anti-tumor activity of 13.56 MHz alternating magnetic hyperthermia and chemotherapy on the induction of apoptosis in human colon cancer cell lines HT29 and HCT116 by up-regulation of Bax, cleaved caspase 3&9, and cleaved PARP proteins

Background

The purpose of the present study was to evaluate the efficacy of chemo-magnetic hyperthermia (MH), a combination of alternating magnetic field (AMF) and superparamagnetic nanoparticles (SPIONs) coated with Polyethylene glycol-Poly(butyl acrylate)-Polyethylene glycol (PEG-PBA-PEG) carrying 5-Fluorouracil (5-Fu), at inducing apoptosis in the human cancer cell lines HT29 and HCT116. This process can be mediated by alterations in the expression of apoptotic effector proteins, including Bax, Bcl-2, cleaved caspase 3&9, and cleaved PARP, which are involved in the intrinsic pathway of apoptosis. For this purpose, the cells were cultured as monolayers. Then both cell lines were treated with 5-Fu/magnetic nanoparticles and magnetic hyperthermia. Finally, the effect of treatment on cancer cells was determined by Western blot analysis and flow cytometry.

Results

Our results showed that combined chemo-magnetic thermotherapy significantly increased the apoptosis in colon cancer cells compared to chemotherapy or hyperthermia alone (P < 0.05). Up-regulation of Bax, cleaved caspase 3&9, and cleaved PARP proteins was indicative of apoptosis induction in cancer cells, which are involved in the intrinsic pathway of apoptosis.

Conclusions

This study demonstrates that localized hyperthermia was able to significantly trigger the 5-Fu release and inhibit cell viability, which, due to the synchronization of hyperthermia and chemotherapy, exacerbated the damage of cancer cells.

Graphical Abstract

Phenylboronic acid-based core-shell drug delivery platform clasping 1,3-dicarbonyl compounds by a coordinate interaction

Along with the successful commercialization of chemotherapeutics, such as doxorubicin and paclitaxel, numerous natural compounds have been investigated for clinical applications. Recently, curcumin (CUR), a natural compound with various therapeutic effects, has attracted attention for cancer immunotherapy. Most chemotherapeutics, however, have poor water solubility due to their hydrophobicity, which makes them less suited to biomedical applications; CUR is no exception because of its low bioavailability and extremely high hydrophobicity. In the present study, we developed an easy but effective strategy using the interaction between the 1,3-dicarbonyl groups of drugs and phenylboronic acid (PBA) to solubilize hydrophobic drugs. First, we verified the coordinate interaction between 1,3-dicarbonyl and PBA using 3,5-heptanedione as a model compound, followed by CUR as a model drug. A PBA-grafted hydrophilic polymer was used to form a nanoconstruct by coordination bonding with CUR, which then made direct administration of the nanoparticles possible. The nanoconstruct exhibited remarkable loading capability, uniform size, colloidal stability, and pH-responsive drug release, attributed to the formation of core-shell nanoconstructs by coordinate interaction. The therapeutic nanoconstructs successfully showed both chemotherapeutic and anti-PD-L1 anticancer effects in cellular and animal models. Furthermore, we demonstrated the applicability of this technique to other 1,3-dicarbonyl compounds. Overall, our findings suggest a facile, but expandable strategy by applying the coordinate interaction between 1,3-dicarbonyl and PBA, which enables high drug loading and stimuli-responsive drug release.

Nitric oxide-releasing micelles with intelligent targeting for enhanced anti-tumor effect of cisplatin in hypoxia

Background

Hypoxic tumor microenvironment (TME) promotes tumor metastasis and drug resistance, leading to low efficiency of cancer chemotherapy. The development of targeted agents or multi-target therapies regulating hypoxic microenvironment is an important approach to overcome drug resistance and metastasis.

Methods

In this study, chitosan oligosaccharide (COS)-coated and sialic acid (SA) receptor-targeted nano-micelles were prepared using film dispersion method to co-deliver cisplatin (CDDP) and nitric oxide (NO) (denoted as CTP/CDDP). In addition, we explored the mechanisms by which NO reversed CDDP resistance as well as enhanced anti-metastatic efficacy in hypoxic cancer cells.

Results

Because of the different affinities of COS and SA to phenylboronic acid (PBA) under different pH regimes, CTP/CDDP micelles with intelligent targeting property increased cellular uptake of CDDP and enhanced cytotoxicity to tumors, but reduced systemic toxicity to normal organs or tissues. In addition, CTP/CDDP showed stimulus-responsive release in TME. In terms of anti-tumor mechanism, CTP/CDDP reduced CDDP efflux and inhibited epithelial-mesenchymal transition (EMT) process of tumor by down-regulating hypoxia-inducible factor-1α (HIF-1α), glutathione (GSH), multidrug resistance-associated protein 2 (MRP2) and matrix metalloproteinase 9 (MMP9) expression, thus reversing drug resistance and metastasis of hypoxic tumor cells.

Conclusions

The designed micelles significantly enhanced anti-tumor effects both in vitro and in vivo. These results suggested that CTP/CDDP represented a promising strategy to treat resistance and metastatic tumors.

Graphic abstract

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-00989-z.

Simultaneous inhibition of planktonic and biofilm bacteria by self-adapting semiconducting polymer dots

Biofilm infections present an enormous challenge in today's healthcare settings. Currently, pH-switchable antibacterial agents are being developed to eradicate biofilms. However, most pH-switchable antibacterial agents are less lethal to planktonic bacteria under neutral conditions, and cannot prevent the dispersed bacteria from seeding acute infection again. Herein, this work reports the applications of semiconducting polymer dots (Pdots) with a double adhesion mechanism in imaging and inhibiting bacteria inside (weak acidic conditions) and outside (neutral conditions) biofilms. Clew-like Pdots were prepared by covalently linking phenylboronic acid (PBA) and pH-responsive naphthalimide (NA) ramification in semiconducting polymers. Under neutral conditions, the Pdots combined with bacteria through the formation of boronate esters between PBA and diols. Under weakly acidic conditions, the partial borate bond fractured, and the Pdots adhered onto the bacterial surface through the positively charged NA in Pdots. Furthermore, the Pdots display negligible toxicity to mammalian cells and tissues. More importantly, the Pdots can selectively damage the bacterial membrane and inhibit bacteria in vivo. This work highlights the feasibility of using semiconducting Pdots to image and inhibit bacteria inside and outside biofilms, which represents a highly effective strategy to cope with biofilm infections.

Injectable stress relaxation gelatin-based hydrogels with positive surface charge for adsorption of aggrecan and facile cartilage tissue regeneration

Background

Cartilage injury and pathological degeneration are reported in millions of patients globally. Cartilages such as articular hyaline cartilage are characterized by poor self-regeneration ability due to lack of vascular tissue. Current treatment methods adopt foreign cartilage analogue implants or microfracture surgery to accelerate tissue repair and regeneration. These methods are invasive and are associated with the formation of fibrocartilage, which warrants further exploration of new cartilage repair materials. The present study aims to develop an injectable modified gelatin hydrogel.

Method

The hydrogel effectively adsorbed proteoglycans secreted by chondrocytes adjacent to the cartilage tissue in situ, and rapidly formed suitable chondrocyte survival microenvironment modified by ε-poly-L-lysine (EPL). Besides, dynamic covalent bonds were introduced between glucose and phenylboronic acids (PBA). These bonds formed reversible covalent interactions between the cis−diol groups on polyols and the ionic boronate state of PBA. PBA-modified hydrogel induced significant stress relaxation, which improved chondrocyte viability and cartilage differentiation of stem cells. Further, we explored the ability of these hydrogels to promote chondrocyte viability and cartilage differentiation of stem cells through chemical and mechanical modifications.

Results

In vivo and in vitro results demonstrated that the hydrogels exhibited efficient biocompatibility. EPL and PBA modified GelMA hydrogel (Gel-EPL/B) showed stronger activity on chondrocytes compared to the GelMA control group. The Gel-EPL/B group induced the secretion of more extracellular matrix and improved the chondrogenic differentiation potential of stem cells. Finally, thus hydrogel promoted the tissue repair of cartilage defects.

Conclusion

Modified hydrogel is effective in cartilage tissue repair.

Supplementary Information

The online version contains supplementary material available at 10.1186/s12951-021-00950-0.

A sequentially responsive nanogel via Pt(IV) crosslinking for overcoming GSH-mediated platinum resistance

Chemotherapy efficiency of platinum(II) (Pt(II)) is often attenuated owing to the low intracellular drugs concentration and glutathione (GSH)-mediated detoxification. To address these problems, we fabricated a step-by-step responsive nanogel (~160 nm) by copolymerization between four functional monomers. Hydrophilic methoxypolyethylene glycols (mPEG) distributedrandomly on the surface of particles endowed the nanogel with "stealth" property in blood circulation, while the chemical crosslinking inside particles by platinum(IV) (Pt(IV)) linker remarkably increased the stability of nanogel in vivo. These advantages of nanogels leaded to higher accumulation at tumor region (6.4% ID/g), followed by triggering the dePEGylation effect by the cleavage of ortho ester at tumoral extracellular pH. Meanwhile, the exposed phenylboric acid (PBA) could significantly increase cellular uptake and intracellular drugs levels by targteing sialic acid residues on the cells membrane. More importantly, this nanogels could further deplete intracellular glutathione (GSH) by the dual-regulation of platinum(IV) and arylboronic ester, resulting in enhanced platinum(II) toxicity both in vitro and in vivo, eventually achieving superior inhibition rate (79.14%) in A549/DDP tumor. Thus, the sequentially responsive nanogel could be considered as an effective strategy for cancer treatment.

Multifunctional polymeric micellar nanomedicine in the diagnosis and treatment of cancer

Polymeric micelles are a prevalent topic of research for the past decade, especially concerning their fitting ability to deliver drug and diagnostic agents. This delivery system offers outstanding advantages, such as biocompatibility, high loading efficiency, water-solubility, and good stability in biological fluids, to name a few. The multifunctional polymeric micellar architect offers the added capability to adapt its surface to meet the looked-for clinical needs. This review cross-talks the recent reports, proof-of-concept studies, patents, and clinical trials that utilize polymeric micellar family architectures concerning cancer targeted delivery of anticancer drugs, gene therapeutics, and diagnostic agents. The manuscript also expounds on the underlying opportunities, allied challenges, and ways to resolve their bench-to-bedside translation for allied clinical applications.

Polymeric Delivery of Therapeutic Nucleic Acids

The advent of genome editing has transformed the therapeutic landscape for several debilitating diseases, and the clinical outlook for gene therapeutics has never been more promising. The therapeutic potential of nucleic acids has been limited by a reliance on engineered viral vectors for delivery. Chemically defined polymers can remediate technological, regulatory, and clinical challenges associated with viral modes of gene delivery. Because of their scalability, versatility, and exquisite tunability, polymers are ideal biomaterial platforms for delivering nucleic acid payloads efficiently while minimizing immune response and cellular toxicity. While polymeric gene delivery has progressed significantly in the past four decades, clinical translation of polymeric vehicles faces several formidable challenges. The aim of our Account is to illustrate diverse concepts in designing polymeric vectors towards meeting therapeutic goals of in vivo and ex vivo gene therapy. Here, we highlight several classes of polymers employed in gene delivery and summarize the recent work on understanding the contributions of chemical and architectural design parameters. We touch upon characterization methods used to visualize and understand events transpiring at the interfaces between polymer, nucleic acids, and the physiological environment. We conclude that interdisciplinary approaches and methodologies motivated by fundamental questions are key to designing high-performing polymeric vehicles for gene therapy.

Activable Multi-Modal Nanoprobes for Imaging Diagnosis and Therapy of Tumors

Malignant tumors have become one of the major causes of human death, but there remains a lack of effective methods for tiny tumor diagnosis, metastasis warning, clinical efficacy prediction, and effective treatment. In this context, localizing tiny tumors via imaging and non-invasively extracting molecular information related to tumor proliferation, invasion, metastasis, and drug resistance from the tumor microenvironment have become the most fundamental tasks faced by cancer researchers. Tumor-associated microenvironmental physiological parameters, such as hypoxia, acidic extracellular pH, protease, reducing conditions, and so forth, have much to do with prognostic indicators for cancer progression, and impact therapeutic administrations. By combining with various novel nanoparticle-based activatable probes, molecular imaging technologies can provide a feasible approach to visualize tumor-associated microenvironment parameters noninvasively and realize accurate treatment of tumors. This review focuses on the recent achievements in the design of “smart” nanomedicine responding to the tumor microenvironment-related features and highlights state-of- the-art technology in tumor imaging diagnosis and therapy.

Active-targeting and acid-sensitive pluronic prodrug micelles for efficiently overcoming MDR in breast cancer

Multidrug resistance (MDR) seriously hinders therapeutic efficacy in clinical cancer treatment. Herein, we reported new polymeric prodrug micelles with tumor-targeting and acid-sensitivity properties based on two different pluronic copolymers (F127 and P123) for enhancing tumor MDR reversal and chemotherapy efficiency in breast cancer. Hybrid micelles were composed of phenylboric acid (PBA)-modified F127 (active-targeting group) and doxorubicin (DOX)-grafted P123 (prodrug groups), which were named as FBP-CAD. FBP-CAD exhibited good stability in a neutral environment and accelerated drug release under mildly acidic conditions by the cleavage of β-carboxylic amides bonds. In vitro studies demonstrated that FBP-CAD significantly increased cellular uptake and drug concentration in MCF-7/ADR cells through the homing ability of PBA and the anti-MDR effect of P123. In vivo testing further indicated that hybrid micelles facilitated drug accumulation at tumor sites as well as reduced side effects to normal organs. The synergistic effect of active-targeting and MDR-reversal leads to the highest tumor growth inhibition (TGI 78.2%). Thus, these multifunctional micelles provide a feasible approach in nanomedicine for resistant-cancer treatment.

Phenylboronic acid conjugated to doxorubicin nanocomplexes as an anti-cancer drug delivery system in hepatocellular carcinoma

Anti-cancer strategies using nanocarrier systems have been explored in a variety of cancers; these systems can easily be incorporated into tumors via the enhanced permeability and retention (EPR) effect leading to enhanced anti-tumor activity while reducing systemic toxicity by specific tumor-targeting. The prognosis of hepatocellular carcinoma (HCC) is extremely poor when the condition is diagnosed at the unresectable stage as treatment options are limited. In order to improve the treatment of cancer and the overall anti-cancer effect, polymerized phenylboronic acid conjugated doxorubicin (pPBA-Dox) nanocomplexes were generated, and conjugated doxorubicin, which is conventionally used in HCC. The nanocomplexes exhibited enhanced anti-tumor activity via tumor-specific targeting in the subcutaneous and orthotopic HCC syngeneic mice tumor model, implying that the nanocomplexes facilitate the targeted Dox delivery to liver cancer in which the sialic acid is over-expressed. Therefore, this study provides insight into the novel targeted therapy using the nanocomplexes for the treatment of HCC.

Stimuli-Responsive Multifunctional Phenylboronic Acid Polymers Via Multicomponent Reactions: From Synthesis to Application

Stimuli-responsive polymers undergo changes under different environmental conditions. Among them, phenylboronic acid (PBA) containing polymers (PBA-polymers) are unique, because they can selectively react with diols to generate borates that are sensitive to pH, sugars, and H₂ O₂ , and can be effectively used to synthesize smart drug carriers and self-healing hydrogels. Recently, multifunctional PBA-polymers (MF-PBA-polymers) have been developed using multicomponent reactions (MCRs) to introduce PBA groups into polymer structures. These MF-PBA-polymers have features similar to those of traditional PBA-polymers; moreover, they exhibit additional properties, such as fluorescence, antimicrobial activity, and antioxidant capability, when different MCRs are used. In this mini review, the preparation of these MF-PBA-polymers are summarized and the new properties/functions that have been introduced into these polymers using different MCRs are discussed. The uses of these MF-PBA-polymers as fluorescent cell anticoagulants, drug carriers, and gelators of functional self-healing hydrogels have been discussed. Additionally, the challenges encountered during their preparation are discussed and also the future developments in this field are touched upon.

Polymer/Aptamer-Integrated Gold Nanoconstruct Suppresses the Inflammatory Process by Scavenging ROS and Capturing Pro-inflammatory Cytokine TNF-α

In the present study, we report a rationally designed polymer/aptamer-integrated gold (Au) nanoconstruct capable of scavenging reactive oxygen species (ROS) and capturing tumor necrosis factor alpha (TNF-α) and investigate its potential as an anti-inflammatory agent for the treatment of peritonitis. By taking advantage of specific interactions between ATP and both ATP aptamer and polymeric phenylboronic acid (pPBA), we construct a unique polymer-coated Au nanoconstruct equipped with TNF-α aptamer and ATP aptamer. The formed phenylboronic ester and TNF-α aptamer in the nanoconstruct is capable of scavenging ROS and capturing of TNF-α, respectively. Thus, this combined characteristics enable the nanoconstruct an additive anti-inflammatory effect. Furthermore, we demonstrate the high anti-inflammatory effect of the nanoconstruct in vitro and in vivo using the peritonitis model by monitoring ROS and pro-inflammatory cytokine levels.

Advances in Multiple Stimuli-Responsive Drug-Delivery Systems for Cancer Therapy

Nanomedicines afford unique advantages in therapeutic intervention against tumors. However, conventional nanomedicines have failed to achieve the desired effect against cancers because of the presence of complicated physiological fluids and the tumor microenvironment. Stimuli-responsive drug-delivery systems have emerged as potential tools for advanced treatment of cancers. Versatile nano-carriers co-triggered by multiple stimuli in different levels of organisms (eg, extracorporeal, tumor tissue, cell, subcellular organelles) have aroused widespread interest because they can overcome sequential physiological and pathological barriers to deliver diverse therapeutic “payloads” to the desired targets. Furthermore, multiple stimuli-responsive drug-delivery systems (MSR-DDSs) offer a good platform for co-delivery of agents and reversing multidrug resistance. This review affords a comprehensive overview on the “landscape” of MSR-DDSs against tumors, highlights the design strategies of MSR-DDSs in recent years, discusses the putative advantage of oncotherapy or the obstacles that so far have hindered the clinical translation of MSR-DDSs.

Nanoassemblies with Effective Serum Tolerance Capability Achieving Robust Gene Silencing Efficacy for Breast Cancer Gene Therapy

The transfection efficiency of siRNA mediated by cationic polymers is limited due to the instability of polymers/siRNA complexes in the presence of serum. Poly(ethylene glycol) (PEG) is usually applied to modify cationic polymers, so as to reduce protein and cell adsorption and then to improve siRNA transfection efficiency. However, the polymers' modification with PEG mostly consumes the free amino of the polymers, which can, in turn, reduce the charge density and limit their siRNA transfection efficacy. Here, a new PEG modification strategy that need not consume the surface aminos of polymers is proposed. Catechol-PEG polymers are coated on the surface of phenylboronic acid (PBA)-modified Generation 5 (G5) poly(amidoamine) dendrimers (G5PBA) via reversible boronate esters to establish PEG-modified dendrimer/siRNA nanoassemblies for efficient siRNA delivery. The PEG/G5PBA/siRNA nanoassemblies have positive charge and show excellent gene silencing efficacy in the absence of serum in vitro. More importantly, the PEG/G5PBA/siRNA nanoassemblies also exhibit excellent serum resistance and gene silencing efficacy in serum-containing medium. Furthermore, the effective antiserum and gene silencing efficacy elicited by these nanoassemblies lead to excellent antitumor effects in vivo. This proposed strategy constitutes an important approach to reach an excellent gene silencing efficacy in the presence of serum.

Polymeric delivery systems for nucleic acid therapeutics: Approaching the clinic

Gene therapy using nucleic acids has many clinical applications for the treatment of diseases with a genetic origin as well as for the development of innovative vaccine formulations. Since nucleic acids in their free form are rapidly degraded by nucleases present in extracellular matrices, have poor pharmacokinetics and hardly pass cellular membranes, carrier systems are required. Suitable carriers that protect the nucleic acid payload against enzymatic attack, prolong circulation time after systemic administration and assist in cellular binding and internalization are needed to develop nucleic acid based drug products. Viral vectors have been investigated and are also clinically used as delivery vehicles. However, some major drawbacks are associated with their use. Therefore there has been substantial attention on the use of non-viral carrier systems based on cationic lipids and polymers. This review focuses on the properties of polymer-based nucleic acid formulations, also referred as polyplexes. Different polymeric systems are summarized, and the cellular barriers polyplexes encounter and ways to tackle these are discussed. Finally attention is given to the clinical status of non-viral nucleic acid formulations.

CO2-Responsive Spherical Polyelectrolyte Brush with Multi-Stimulation for Reversible Protein Immobilization and Release

Multi-responsive materials have received extensive interest in many areas due to their smart characteristics. This paper presents rationally designed multi-responsive spherical polyelectolyte brushes composed of a solid polystyrene (PS) core and a poly (2-(dimethylamino) ethyl methacrylate) (PDMAEMA) shell synthesized by photoemulsion polymerization. Based on dynamic light scattering, Zeta potential, turbidity measurements, isothermal titration calorimetry, and UV-vis spectroscopy, PS-PDMAEMA works as a good potential adsorbent for bovine serum albumin (BSA) for which the maximum adsorption capability could reach up to 5190mg g−1. Moreover, the immobilization and release of protein on the polymer brush could be adjusted with different triggers, including the pH, ionic strength, and temperature. Furthermore, the green gas triggers, CO2 and N2, could be employed in the BSA@ PS-PDMAEMA system by easily bubbling over many cycles without any salt accumulation. The main reason for the observed actions is the brushes could be switched alternately between extended and collapsed states with different stimulations. Upon comparing the circular dichroism spectra of original and released BSA after many cycles of adsorption and release, it’s clear that the protein can retain its initial biological activity after release from the PS-PDMAEMA. This work provides an effective and green way to immobilize and release proteins in biotechnology.

Nanogels with Selective Intracellular Reactivity for Intracellular Tracking and Delivery

A multimodal approach for hydrogel-based nanoparticles was developed to selectively allow molecular conjugated species to either be released inside the cell or remain connected to the polymer network. Using the intrinsic difference in reactivity between esters and amides, nanogels with an amide-conjugated dye could be tracked intracellularly localizing next to the nucleus, while ester-conjugation allowed for liberation of the molecular species from the hydrogel network inside the cell, enabling delivery throughout the cytoplasm. The release was a result of particle exposure to the intracellular environment. The conjugation approach and polymer network building rely on the same chemistry and provide a diverse range of possibilities to be used in nanomedicine and theranostic approaches.

Non-isotope enriched phenylboronic acid-decorated dual-functional nano-assembles for an actively targeting BNCT drug

The feasibility of boron neutron capture therapy (BNCT) greatly depends on the selective accumulation of ¹⁰B in tumors. The p-boronophenylalanine-fructose (BPA-f) complex has been established as a conventional BNCT agent due to its preferential uptake into tumors, which is driven by amino acid transporters. However, the retention of BPA-f in tumors is highly limited because of an antiport mechanism, which is regulated by a gradient of amino acid concentration across the cancer cell membrane. Thus, to preserve a high ¹⁰B concentration in tumors, patients are inevitably subjected to a constant intravenous infusion. To this end, we employed a phenylboronic acid (PBA)-decorated polymeric nanoparticle (Nano^PBA) as a sialic acid-targeting BNCT agent. In this manner, the PBA can exhibit dual functionalities, i.e., exhibiting a neutron capture capacity and hypersialyated cancer cell targeting effect. Our developed Nano^PBA possesses a supramolecular structure composed of a core and shell comprised of poly(lactic acid) (PLA) and poly(ethylene glycol) (PEG) segments, respectively. The PBA moiety is installed at the PEG end, providing an unusually strong targeting effect, supposedly via multivalent binding onto the cancer cell membrane. As in BNCT, we verified the feasibility of Nano^PBA against a B16 melanoma-bearing mouse model. By virtue of efficient tumor targeting, even at a 100-fold lower dose than BPA-f, the Nano^PBA achieved a potent antitumor effect.

Polymeric Nanoparticles Controlled by On-Chip Self-Assembly Enhance Cancer Treatment Effectiveness

Nanoparticle (NP)-based drug delivery systems or nanomedicines have broadened the horizon of translational research for decades. Conventional bulk mixing synthesis methods have impeded successful clinical translations of nanomedicines due to the limited ability of the controlled, scalable production with high uniformity. Herein, an on-chip preparation of self-assembled, drug-encapsulated polymeric NPs is presented for their improved uniformity and homogeneity that results in enhanced anti-cancer effect in vitro and in vivo. The NPs are formulated through rapid convective mixing of two aqueous solutions of a hydrophilic polymer and an anti-cancer drug, doxorubicin (DOX), in the swirling microvortex reactor (SMR). Compared to conventional bulk-mixed NPs (BMPs), the microvortex-synthesized NPs (MVPs) exhibit narrower size distributions and better size tunability. It is found that the improved uniformity and homogeneity of the MVPs not only enhance cellular uptake and anti-cancer effect with pH-responsive drug release in vitro, but also result in an improved tumor regression and decreased side effects at off-targeted organs in vivo. The findings demonstrate that uniformly designed NPs with more homogeneous properties can induce a significant enhancement of an anti-cancer effect in vivo. The results show the potential of a high-speed on-chip synthesis as a scalable manufacturing platform for reliable clinical translations of nanomedicines.

Medical Applications Based on Supramolecular Self-Assembled Materials From Tannic Acid

Polyphenol, characterized by various phenolic rings in the chemical structure and an abundance in nature, can be extracted from vegetables, grains, chocolates, fruits, tea, legumes, and seeds, among other sources. Tannic acid (TA), a classical polyphenol with a specific chemical structure, has been widely used in biomedicine because of its outstanding biocompatibility and antibacterial and antioxidant properties. TA has tunable interactions with various materials that are widely distributed in the body, such as proteins, polysaccharides, and glycoproteins, through multimodes including hydrogen bonding, hydrophobic interactions, and charge interactions, assisting TA as important building blocks in the supramolecular self-assembled materials. This review summarizes the recent immense progress in supramolecular self-assembled materials using TA as building blocks to generate different materials such as hydrogels, nanoparticles/microparticles, hollow capsules, and coating films, with enormous potential medical applications including drug delivery, tumor diagnosis and treatment, bone tissue engineering, biofunctional membrane material, and the treatment of certain diseases. Furthermore, we discuss the challenges and developmental prospects of supramolecular self-assembly nanomaterials based on TA.

Apoptosis pathway in the combined treatment of x-ray and 5-FU-loaded triblock copolymer-coated magnetic nanoparticles

Aim: In this study, the effects of ionizing radiation and 5-fluorouracil (5-FU)-loaded triblock copolymer-coated magnetic nanoparticles (NPs) on the induction of apoptosis in HT-29 and HCT-116 were investigated. Materials & methods: The percentage of apoptotic cells and alteration of the expression of apoptotic-related proteins were evaluated in treated cells by flow cytometry and western blot analysis, respectively. Results: Combination treatment with 5-FU and radiation had a stronger effect on decreasing Bcl-2 expression and increasing expression of Bax, cleaved caspase-9, cleaved caspase-3, cleaved PARP compared with each treatment alone. Conclusion: The combination of radiation and triblock copolymer-coated magnetic NPs as 5-FU drug carriers works by triggering apoptosis to improve in vitro treatment efficacy. Additional study may present the NPs as an effective approach for the treatment of colon cancer.

Tumor microenvironment responsive drug delivery systems

Conventional tumor-targeted drug delivery systems (DDSs) face challenges, such as unsatisfied systemic circulation, low targeting efficiency, poor tumoral penetration, and uncontrolled drug release. Recently, tumor cellular molecules-triggered DDSs have aroused great interests in addressing such dilemmas. With the introduction of several additional functionalities, the properties of these smart DDSs including size, surface charge and ligand exposure can response to different tumor microenvironments for a more efficient tumor targeting, and eventually achieve desired drug release for an optimized therapeutic efficiency. This review highlights the recent research progresses on smart tumor environment responsive drug delivery systems for targeted drug delivery. Dynamic targeting strategies and functional moieties sensitive to a variety of tumor cellular stimuli, including pH, glutathione, adenosine-triphosphate, reactive oxygen species, enzyme and inflammatory factors are summarized. Special emphasis of this review is placed on their responsive mechanisms, drug loading models, drawbacks and merits. Several typical multi-stimuli responsive DDSs are listed. And the main challenges and potential future development are discussed.