Thermo/redox/pH-triple sensitive poly(N-isopropylacrylamide-co-acrylic acid) nanogels for anticancer drug delivery

Enhancing the antitumor activity of tea polyphenols encapsulated in biodegradable nanogels by macromolecular self-assembly

Nanogels (NGs) with desirable stability have emerged as a promising platform for biomedical applications. Herein, a convenient approach was developed to encapsulate and protect tea polyphenols (TPs) by macromolecular self-assembly of lysozyme (Ly) and carboxymethyl cellulose (CMC) through a heating treatment. Biodegradable Ly–CMC NGs were formed on the basis of molecules driven by electrostatic interaction and hydrophobic forces. The particle size and morphology of the Ly–CMC NGs were analyzed using a Malvern particle size analyzer, fluorescence spectrophotometer, and scanning electron microscope. The results showed that the heated NGs were spherical with better stability and smaller particle size. The encapsulation efficiency of TP-loaded NGs was 89.05 ± 3.14%, and it indicated that the Ly–CMC NGs may have a strong binding force with TPs. Moreover, TP-loaded NGs showed a sustained release feature. The DPPH and ABTS-scavenging rates of the TP-loaded NGs were 76.5% and 86.1%, respectively. The antitumor activity of the TP-loaded NGs can effectively inhibit the proliferation of HepG₂ cells. Furthermore, TP-loaded NGs were proven to significantly enhance the induction of apoptosis in hepatoma cells and exhibit obvious cell cycle arrest. Our results demonstrate that the Ly–CMC NGs have extensive application prospects as a biocompatible and biodegradable delivery carrier of food functional factors to improve their antitumor effects.

Fabrication of biodegradable TP-loaded Ly and CMC nanogels via self-assembly and the study of their controlled release and absorption process in vivo.

Smart co-delivery of 6-mercaptopurine and methotrexate using disulphide-based PEGylated-nanogels for effective treatment of breast cancer

Smart co-delivery of 6-mercaptopurine and methotrexate using disulphide-based PEGylated-nanogels.

Triply responsive coumarin-based microgels with remarkably large photo-switchable swelling

Using two different wavelengths of UV light enables remarkably strong photo-switchable swelling of pH- and temperature-responsive microgels and photo-release of doxorubicin.

An NIR-triggered drug release and highly efficient photodynamic therapy from PCL/PNIPAm/porphyrin modified graphene oxide nanoparticles with the Janus morphology

This project aimed to investigate the synthesis and characteristics of stimuli-responsive nanoparticles with different morphologies. In the first step, graphene oxide was synthesized based on the improved Hummers' method. Then, thermo-responsive poly(N-isopropylacrylamide-co-N-(hydroxymethyl)acrylamide), an amphiphilic copolymer, and poly(caprolactone) (PCL), a hydrophobic polymer, were used to prepare Janus and mixed graphene oxide-based nanoparticles. Fluorescence microscopy was utilized to confirm the Janus structure by labeling the mixed and Janus NPs with fluorescent hydrophobic and hydrophilic dyes via a solvent-evaporation method. Then, terminally modified carboxyl porphyrin (TPPC3-COOH), used as the second generation photosensitizer, was grafted to the copolymer surrounding the mixed and Janus NPs. Next, quercetin, a hydrophobic anti-cancer drug, was loaded onto both NPs to accomplish NIR-triggered photodynamic- and chemo-therapy. Finally, the drug loading, encapsulation efficiency, and in vitro release of thermo-responsive NPs were investigated at temperatures of 37 °C and 40 °C as well as under laser irradiation (808 nm).

This project aimed to investigate the synthesis and characteristics of stimuli-responsive nanoparticles with different morphologies.

Smart pH-Sensitive Nanogels for Controlled Release in an Acidic Environment

The encapsulation of therapeutic compounds into nanosized delivery vectors has become an important strategy to improve efficiency and reduce side effects in drug delivery applications. Here, we report the synthesis of pH-sensitive nanogels, which are based on the monomer N-[(2,2-dimethyl-1,3-dioxolane)methyl]acrylamide (DMDOMA) bearing an acid cleavable acetal group. Degradation studies revealed that these nanogels hydrolyze under acidic conditions and degrade completely, depending on the cross-linker, but are stable in physiological environment. The best performing system was further studied regarding its release kinetics using the anticancer drug doxorubicin. In vitro studies revealed a good compatibility of the unloaded nanogel and the capability of the doxorubicin loaded nanogel to mediate cytotoxic effects in a concentration and time-dependent manner with an even higher efficiency than the free drug. Based on the investigated features, the presented nanogels represent a promising and conveniently prepared alternative to existing carrier systems for drug delivery.

Redox-responsive nano-carriers as tumor-targeted drug delivery systems

With ever increasing scientific knowledge and awareness, research is underway around the globe to design new types of stimuli (external/internal) responsive nano-carriers for biotechnological applications at large and biomedical/pharmaceutical in particular. Based on literature evidence, stimuli-responsive carriers have been classified into four major categories, i.e. (1) physical, (2) chemical, (3) biological, and (4) dual (combination of any of the first three classes). Among various types, redox-responsive nano-carriers are of supreme interests and discussed here in this review. The difference in redox potential in tumor and normal tissue is considered as a potential target for tumor targeting leading to the development of redox-responsive drug delivery systems (DDS). In this regard, a high concentration of glutathione in tumor/intracellular environment has extensively been exploited. Disulfide bonds were found as a promising tool for designing redox-responsive which tend to cleave in a reductive environment forming sulfhydryl groups. Many nano-carriers have been explored widely to control tumor growth. These systems were used against the tumor xenograft animal model and showed improved tumor targeting with tumor growth inhibition. Herein, an effort has been made to summarize various aspects from design to development of numerous types of redox-responsive DDS including liposomes, micelles, nanoparticles, nanogel and prodrug based nanomedicines. An emphasis is also given on various types of nano-carriers with special reference to the tumor-targeted drug delivery applications. Also, dual responsive nano-carriers (in addition to redox-responsive) have also been briefly discussed. Towards the end of the chapter, the information is also given on their future perspectives.

Reduction-sensitive polymeric nanomedicines: An emerging multifunctional platform for targeted cancer therapy

The development of smart delivery systems that are robust in circulation and quickly release drugs following selective internalization into target cancer cells is a key to precision cancer therapy. Interestingly, reduction-sensitive polymeric nanomedicines showing high plasma stability and triggered cytoplasmic drug release behavior have recently emerged as one of the most exciting platforms for targeted delivery of various anticancer drugs including small chemical drugs, proteins, and nucleic acids. In vivo studies in varying tumor models reveal that these reduction-sensitive multifunctional nanomedicines outperform the currently used clinical formulations and reduction-insensitive counterparts, bringing about not only significantly enhanced tumor selectivity, accumulation and inhibition efficacy but also markedly reduced systemic toxicity and improved therapeutic index. In this review, we will highlight the cutting-edge advancement with a focus on in vivo performances as well as future perspectives on reduction-sensitive polymeric nanomedicines for targeted cancer therapy.

Non-dye cell viability monitoring by using pH-responsive inverse opal hydrogels

Recent advances in the field of drug screening focus on accurate, rapid and high-throughput screening methods. In our work, hydrogel inverse opal photonic crystal microspheres (HPCMs) were fabricated through a templating method and exhibited a robust and reversible response to temperature and pH. The response performance was tested under various temperature (25-55 °C) and pH (1.5-7.5) conditions and the reflective peak shifted noticeably within the visible wavelength range. Furthermore, HPCMs were used as drug delivery carriers and not only displayed high doxorubicin (DOX) drug loading but also presented thermo/pH-induced drug release properties. More importantly, these carriers were shown to be good reporters for monitoring cell viability due to their tunable colour variation. This capability was applied to H460 cell cultures with or without DOX. The structure colour of HPCMs varied in different cell culture microenvironments, and cell apoptosis was able to be distinguished. In this way, this fast, non-dyeing method for reporting cell viability in tumour cytotoxicity assays has potential in the field of drug screening and may give new insights into the use of structural colour to report results in drug screening systems.

Redox-Responsive Core-Cross-Linked Block Copolymer Micelles for Overcoming Multidrug Resistance in Cancer Cells

Success of chemotherapy as a treatment for cancer has been often inhibited by multidrug resistance (MDR) of the cancer cells. There is a clear need to generate strategies to overcome this resistance. In this work, we have developed redox-responsive and core-cross-linked micellar nanocarriers using poly(ethylene glycol)-block-poly(2-(methacryloyloxy)ethyl 5-(1,2-dithiolan-3-yl)pentanoate) diblock copolymers (PEG-b-PLAHEMA) with tunable swelling properties for the delivery of drugs toward drug-sensitive MDA-MB-231 and drug-resistant MDA-MB-231 (231R) cancer cells. PEG-b-PLAHEMA containing varying number of 2-(methacryloyloxy)ethyl 5-(1,2-dithiolan-3-yl)pentanoate (LAHEMA) units were synthesized by employing the reversible addition-fragmentation chain transfer polymerization technique. The block copolymer self-assembly, cross-linking induced by reduction, and de-cross-linking triggered time-dependent controlled swelling of micelles were studied using dynamic light scattering, fluorescence spectroscopy, and transmission electron microscopy. In vitro cytotoxicity, cellular uptake efficiency, and glutathione-responsive anticancer activity of doxorubicin (DOX) encapsulated in core-cross-linked block copolymer micelles (CCMs) toward both drug-sensitive and drug-resistant cancer cell lines were evaluated. Significant reduction in IC₅₀ was observed by DOX-loaded CCMs toward drug-resistant 231R cancer cell lines, which was further improved by coencapsulating DOX and verapamil (a P-glycoprotein inhibitor) in CCMs. Thus, these reduction-sensitive biocompatible CCMs with tunable swelling property are very promising in overcoming MDR in cancer cells.

Design of Phase-Changeable and Injectable Alginate Hydrogel for Imaging-Guided Tumor Hyperthermia and Chemotherapy

The objective of the present study was to construct an alginate (AG)-based phase-changeable and injectable hydrogel for imaging-guided tumor hyperthermia and chemotherapy. Based on the binding between the α-l-guluronic blocks of AG and calcium ions, the AG/MoS₂/Bi₂S₃-poly(ethylene glycol) (MBP)/doxorubicin (DOX) solution formed a cross-linked hydrogel to simultaneously encapsulate MBP nanosheets and DOX within the hydrogel matrix. The in situ formed hydrogel can act as a reservoir to control the release of entrapped drug molecules, and the doped MBP nanosheets and DOX can realize computed tomography/photoacoustic dual-modal imaging-guided in vivo tumor photothermal therapy and chemotherapy, respectively. The AG/MBP/DOX hydrogel exhibited excellent photothermal conversion properties with mass extinction coefficient of 45.1 L/g/cm and photothermal conversion efficiency of 42.7%. Besides, the heat from the photothermal transformation of MBP can promote drug diffusion from the hydrogel to realize on-demand drug release. Additionally, the hydrogel system can restrain MBP and DOX from entering into the blood stream during therapy, and therefore substantially decrease their side effects on normal organs. More importantly, the drug loading of the AG hydrogel was general and can be extended to the encapsulation of antibiotics, such as amoxicillin, for the prevention of postoperative infections.

A novel polymeric micelle-decorated Fe3O4/Au core–shell nanoparticle for pH and reduction-responsive intracellular co-delivery of doxorubicin and 6-mercaptopurine

The synergistic antitumor activity against MCF-7 cells was confirmed by co-delivery of doxorubicin and 6-mercaptopurine via dual pH/reduction-responsive nanoparticles.

Poly(2-methacryloyloxyethyl phosphorylcholine)-based biodegradable nanogels for controlled drug release

We developed reduction degradable PMPC nanogels for controlled drug releaseviaprecipitation polymerization using a disulfide-containing crosslinker.

Drug-mediation formation of nanohybrids for sequential therapeutic delivery in cancer cells

In order to overcome the multidrug resistance (MDR) of tumor cells, it is very important to develop nanocarriers which can effectively load drugs while releasing them in a sequential way. Herein, nanohybrids with such properties have been fabricated by a first loading of one anticancer drug onto a silicate nanodisk (Laponite (LP), 25 nm in diameter and 0.92 nm in thickness) and a subsequent assembly with a pH sensitive poly(N-vinylpyrrolidone) (PVP) as a protective layer, followed by a loading of with another anticancer drug. The resulting nanohybrids (LDPM) present a high drug encapsulation efficiency and long-term colloidal stability. However, if the two drugs are loaded onto LP before PVP decoration, the formed particles tend to form microsized aggregates with poor colloidal stability. In vitro release study indicates that LDPM can deliver the anticancer drugs in a sequential way, which can be further accelerated under acidic microenvironments mimicking both solid tumor and endo-lysosomal compartments, exerting synergistic anticancer cytotoxicity. The drug-mediated formation of nanocarriers may enlighten a design of novel nanoplatform for co-delivery of therapeutic agents, beyond anticancer drugs, in a combinative way for drug delivery applications.

Design of injectable agar-based composite hydrogel for multi-mode tumor therapy

We designed an injectable hydrogel by dissolving MoS₂/Bi₂S₃-PEG (MBP), doxorubicin (DOX) and agar into water for the concurrent tumor photothermal and chemotherapy. The formed solution was able to be intra-tumorally (I.T.) administered into tumor at a relatively high temperature and automatically formed a hydrogel after cooling to body temperature. The resultant Agar/MBP/DOX (AMD) hydrogel can act as a macro-vessel to retain the MBP nanosheet and DOX and restrict their access to body fluid circulation. Moreover, AMD hydrogel did not compromise the photoacoustic and computed tomography imaging capacity, as well as the photothermal and chemotherapy efficiency of MBP nanosheets and DOX. The heat from the photothermal transformation of MBP nanosheet can promote the drug-release from the hydrogel and thus enable an on-demand drug release. Furthermore, antibiotics were also able to be encapsulated in the hydrogel to avoid the potential wound infection during tumor surgery.

Poly(N-isopropylacrylamide) and Copolymers: A Review on Recent Progresses in Biomedical Applications

The innate ability of poly(N-isopropylacrylamide) (PNIPAAm) thermo-responsive hydrogel to copolymerize and to graft synthetic polymers and biomolecules, in conjunction with the highly controlled methods of radical polymerization which are now available, have expedited the widespread number of papers published in the last decade-especially in the biomedical field. Therefore, PNIPAAm-based hydrogels are extensively investigated for applications on the controlled delivery of active molecules, in self-healing materials, tissue engineering, regenerative medicine, or in the smart encapsulation of cells. The most promising polymers for biodegradability enhancement of PNIPAAm hydrogels are probably poly(ethylene glycol) (PEG) and/or poly(ε-caprolactone) (PCL), whereas the biocompatibility is mostly achieved with biopolymers. Ultimately, advances in three-dimensional bioprinting technology would contribute to the design of new devices and medical tools with thermal stimuli response needs, fabricated with PNIPAAm hydrogels.

Chitosan based nanogels stepwise response to intracellular delivery kinetics for enhanced delivery of doxorubicin

Chitosan based nanogels with pH/redox sensitivities tunable to stepwise response to intracellular delivery kinetics were developed. The nanogels were simply constructed by ionic gelation first, between O-Carboxymethyl-chitosan (CMCS) and thiolated chitosan (TCS), and then oxidation to form disulfide bonds for CMCS-TCS nanogels (CTNGs). Doxorubicin loaded nanogels (DOX/CTNGs) exhibited desirable stability under physiological pH with a mean size of 150.5nm, and quickly aggregated at pH 5.5 (mimic endo/lysosomes) due to protonation of the carboxyl groups on CMCS. DOX/CTNGs would maintain their TCS skeleton in acidic pH and compromised as treated with 10mM glutathione (mimic cytosol). In agreement with the structural variation, release of DOX was dramatically enhanced by the synergetic effects of acidic pH and reductive potential. Stepwise responses to intracellular delivery kinetics were evidenced by laser confocal images showing that DOX/CTNGs underwent efficient cellular internalization through endocytosis, endo/lysomse escape via self-precipitation, cleavage of disulfide linkage in cytosol and disintegration in nucleus, achieving enhanced nuclear delivery and rapid release of doxorubicin. DOX/CTNGs exerted comparable or higher anticancer efficacies than that of free DOX against hela cells. The simple construction of the nanogels and their capacity of enhancing anticancer activities of DOX are potential for translational applications in cancer chemotherapy.

Formation of graphene oxide-hybridized nanogels for combinative anticancer therapy

The low efficacy and high toxicity of chemotherapy have been driving increasing attention on development of combined anticancer therapy technique. In the current work, graphene oxide (GO)-hybridized nanogels (AGD) were developed for delivery of an anticancer drug (doxorubicin (DOX)), which simultaneously presented photothermal therapeutic effects against cancer cells. AGD nanogels were fabricated by in situ incorporating GO nanoplatelets into a biodegradable polymer (alginate) via a double emulsion approach using a disulfide molecule as crosslinker, followed by DOX encapsulation via electrostatic interactions. The nanogels released DOX drug in an accelerated way under both acidic and reducible conditions mimicking extracellular tumor microenvironments and intracellular compartments. The stimulative release controllability of the nanogels improved the DOX internalization and long-term drug accumulation inside A549 cells (an adenocarcinoma human alveolar basal epithelial cell line), which, together with their photothermal effect, resulted in a good anticancer cytotoxicity, indicating their promising potential for combinative anticancer therapy.

Intelligent Textiles with Comfort Regulation and Inhibition of Bacterial Adhesion Realized by Cross-Linking Poly(n-isopropylacrylamide-co-ethylene glycol methacrylate) to Cotton Fabrics

Comfort regulation and inhibition of bacterial adhesion to textiles is realized by cross-linking thermoresponsive random copolymer to the cotton fabrics. By introduction of ethylene glycol methacrylate (EGMA) monomers into n-isopropylacrylamide (NIPAM) with a molar ratio of 2:18, the obtained random copolymer poly(n-isopropylacrylamide-co-ethylene glycol methacrylate), abbreviated as P(NIPAM-co-EGMA), presents a transition temperature (TT) of 40 °C in an aqueous solution with a concentration of 1 mg/mL. Because of the additional EGMA in the copolymer, the obtained P(NIPAM-co-EGMA) shows a glass transition temperature (T_g) of 0 °C, which is much lower than that of pure PNIPAM (T_g = 140 °C). Therefore, the introduction of P(NIPAM-co-EGMA) into the cotton fabrics will have little influence on the softness of the fabrics. Due to the cross-linked P(NIPAM-co-EGMA) layer on the cotton fabrics, the porosity of the polymer layer can be adjusted by varying the external temperature below or above TT, showing that regulation of the air and moisture permeability as well as the body comfort are feasible in the cotton fabrics cross-linked with P(NIPAM-co-EGMA). In addition, the cross-linked P(NIPAM-co-EGMA) layer is capable of absorbing moisture in the ambient atmosphere to form a hydrated layer on top, which can inhibit bacterial adhesion to the textiles.

Rational design of dendritic thermoresponsive nanogels that undergo phase transition under endolysosomal conditions

In the last few decades, the synthesis of nanodevices has become a very active research field with many applications in biochemistry, biotechnology, and biomedicine. However, there is still a great need for smart nanomaterials that can sense and respond to environmental changes. Temperature- and pH-responsive nanogels (NGs), which are prepared in a one-pot synthesis from N-isopropylacrylamide (NiPAm) and a Newkome-type dendron (ABC) bearing carboxylic acid groups, are being investigated as multi-responsive drug carriers. As a result, NGs have been developed that are able to undergo a reversible volume phase transition triggered by acidic conditions, like the ones found in endolysosomal compartments of cancer cells. The NGs have been thoroughly characterized using dynamic light scattering and spectroscopies, such as infrared, nuclear magnetic resonance, UV-visible, and stimulated Raman. Strong hydrogen bonds have been detected when the ABC moieties are deprotonated, which has led to changes in the transition temperatures of the NGs and a reversible, pH-dependent aggregation. This pH-dependent phase change was exploited for the effective encapsulation and sustained release of the anticancer drug cisplatin and resulted in a faster release of the drug at endolysosomal pH values. The cisplatin-loaded NGs have exhibited high toxicities against A549 cells in vitro, while the unloaded NGs have been found to be not cytotoxic and hemocompatible.

A degradable nanogel drug carrier crosslinked with three-oligonucleotide hybrids for two-way drug release in mild and high hyperthermia treatment

Three-segment oligonucleotide hybrids introduced as crosslinkers to a PNIPA–AAc nanonetwork can be specifically transformed and degraded. Architecture of presented carrier helped to achieve enhanced drug loading and tunable and degradable gel properties, and to control release of the drug.

Overcoming multidrug resistance through co-delivery of ROS-generating nano-machinery in cancer therapeutics

The use of nanotechnology to overcome multidrug resistance (MDR) in cancer cells has been predominant.

Photo, pH and redox multi-responsive nanogels for drug delivery and fluorescence cell imaging

A light, pH and redox triple-responsive spiropyran-based nanogel is prepared and applied for the efficient delivery of anticancer drugs and fluorescence cell imaging for the strong emission of merocyanine photoisomers.

Temperature-Responsive Smart Nanocarriers for Delivery Of Therapeutic Agents: Applications and Recent Advances

Smart drug delivery systems (DDSs) have attracted the attention of many scientists, as carriers that can be stimulated by changes in environmental parameters such as temperature, pH, light, electromagnetic fields, mechanical forces, etc. These smart nanocarriers can release their cargo on demand when their target is reached and the stimulus is applied. Using the techniques of nanotechnology, these nanocarriers can be tailored to be target-specific, and exhibit delayed or controlled release of drugs. Temperature-responsive nanocarriers are one of most important groups of smart nanoparticles (NPs) that have been investigated during the past decades. Temperature can either act as an external stimulus when heat is applied from the outside, or can be internal when pathological lesions have a naturally elevated termperature. A low critical solution temperature (LCST) is a special feature of some polymeric materials, and most of the temperature-responsive nanocarriers have been designed based on this feature. In this review, we attempt to summarize recent efforts to prepare innovative temperature-responsive nanocarriers and discuss their novel applications.

In Situ formation of pH-/thermo-sensitive nanohybrids via friendly-assembly of poly(N-vinylpyrrolidone) onto LAPONITE®

Decoration of silicate nanodisks with a pH-sensitive polymer allows for the effective delivery of an anticancer drug in cancer cells with high efficacy.

Cisplatin and doxorubicin dual-loaded mesoporous silica nanoparticles for controlled drug delivery

Multicomponent therapeutic platforms have been proposed to minimize dosage of each drug and reduce toxicity, leading to achieving a synergistic effect and maximizing therapeutic efficacy.

Development of novel hydrogels based on Salecan and poly(N-isopropylacrylamide-co-methacrylic acid) for controlled doxorubicin release

We designed a novel semi-interpenetrating polymer network hydrogel for the controlled delivery of doxorubicin.

Triple-Stimuli-Responsive Ferrocene-Containing PEGs in Water and on the Surface

Triple-stimuli-responsive PEG-based materials are prepared by living anionic ring-opening copolymerization of ethylene oxide and vinyl ferrocenyl glycidyl ether and subsequent thiol-ene postpolymerization modification with cysteamine. The hydrophilicity of these materials can be tuned by three stimuli: (i) temperature (depending on the comonomer ratio), (ii) oxidation state of iron centers in the ferrocene moieties, and (iii) pH-value (through amino groups), both in aqueous solution and at the interface after covalent attachment to a glass surface. In such materials, the cloud point temperatures are adjustable in solution by changing oxidation state and/or pH. On the surface, the contact angle increases with increasing pH and temperature and after oxidation, making these smart surfaces interesting for catalytic applications. Also, their redox response can be switched by temperature and pH, making this material useful for catalysis and electrochemistry applications. Exemplarily, the temperature-dependent catalysis of the chemiluminescence of luminol (a typical blood analysis tool in forensics) was investigated with these polymers.

Self-assembly of pH-sensitive fluorinated peptide dendron functionalized dextran nanoparticles for on-demand intracellular drug delivery

In this study, the amphiphilic fluorinated peptide dendrons functionalized dextran (FPD-HZN-Dex) via an acid-sensitive hydrazone linkage was successfully designed and prepared for the first time. We demonstrated a spontaneous self-assembly of amphiphilic FPD-HZN-Dex into the well-defined nanoparticles with the core-shell architecture in aqueous media, which is attributed to the efficient amphiphilic functionalization of dextran by the hydrophobic fluorinated peptide dendrons. The spherical morphology, uniform particle size and good storage stability of the prepared FPD-HZN-Dex nanoparticles were characterized by dynamic light scattering and transmission electron microscopy, respectively. In vitro drug release studies showed a controlled and pH dependent hydrophobic drug release profile. The cell viability assays show excellent biocompatibility of the FPD-HZN-Dex nanoparticles for both normal cells and tumor cells. Moreover, the FPD-HZN-Dex self-assembled systems based on pH-sensitive hydrazone linkage also can serve as stimulus bioresponsive carriers for on-demand intracellular drug delivery. These self-assembled nanoparticles exhibit a stimulus-induced response to endo/lysosome pH (pH 5.0) that causes their disassembly over time, enabling controlled release of encapsulated DOX. This work has unveiled a unique non-covalent interaction useful for engineering amphiphilic dendrons or dendrimers self-assembled systems.

Stable and degradable microgels linked with cystine for storing and environmentally triggered release of drugs

Microgels crosslinked with a cysteine derivative, which has ability to control gel degradation and trigger drug release.

A redox stimuli-responsive superparamagnetic nanogel with chemically anchored DOX for enhanced anticancer efficacy and low systemic adverse effects

DOX anchored via disulfide onto alginate coated superparamagnetic nanoparticles promised high efficacy with low systemic adverse effects.