A pH-responsive nanoplatform with dual-modality imaging for enhanced cancer phototherapy and diagnosis of lung metastasis.

To address the limitations of traditional photothermal therapy (PTT)/ photodynamic therapy (PDT) and real-time cancer metastasis detection, a pH-responsive nanoplatform (NP) with dual-modality imaging capability was rationally designed. Herein, 1 H,1 H-undecafluorohexylamine (PFC), served as both an oxygen carrier and a 19F magnetic resonance imaging (MRI) probe, and photosensitizer indocyanine green (ICG) were grafted onto the pH-responsive peptide hexahistidine (H6) to form H6-PFC-ICG (HPI). Subsequently, the heat shock protein 90 inhibitor, gambogic acid (GA), was incorporated into hyaluronic acid (HA) modified HPI (HHPI), yielding the ultimate HHPI@GA NPs. Upon self-assembly, HHPI@GA NPs passively accumulated in tumor tissues, facilitating oxygen release and HA-mediated cell uptake. Once phagocytosed by lysosomes, protonation of H6 was triggered due to the low pH, resulting in the release of GA. With near-infrared laser irradiation, GA-mediated decreased HSP90 expression and PFC-mediated increased ROS generation amplified the PTT/PDT effect of HHPI@GA, leading to excellent in vitro and in vivo anticancer efficacies. Additionally, the fluorescence and 19F MRI dual-imaging capabilities of HHPI@GA NPs enabled effective real-time primary cancer and lung metastasis monitoring. This work offers a novel approach for enhanced cancer phototherapy, as well as precise cancer diagnosis.

Novel pH-responsive alginate-stabilized curcumin-selenium-ZIF-8 nanocomposites for synergistic breast cancer therapy.

In this study, a novel selenium@zeolitic imidazolate framework core/shell nanocomposite stabilised with alginate was used to improve the anti-tumour activity of curcumin. The developed alginate-stabilised curcumin-loaded selenium@zeolitic imidazolate framework (Alg@Cur@Se@ZIF-8) had a mean diameter of 159.6 nm and polydispersity index < 0.25. The release of curcumin from the nanocarrier at pH 5.4 was 2.69 folds as high as at pH 7.4. The bare nanoparticles showed haemolytic activity of about 12.16% at a concentration of 500 µg/mL while covering their surface with alginate reduced this value to 5.2%. By investigating cell viability, it was found that Alg@Cur@Se@ZIF-8 caused more cell death than pure curcumin. Additionally, in vivo studies showed that Alg@Cur@Se@ZIF-8 dramatically reduced tumour growth compared to free curcumin in 4T1 tumour-bearing mice. More importantly, the histological study confirmed that the developed drug delivery system successfully inhibited lung and liver metastasis while causing negligible toxicity in vital organs. Overall, due to the excellent inhibitory activity on cancerous cell lines and tumour-bearing animals, Alg@Cur@Se@ZIF-8 can be considered promising for breast cancer therapy.

Citrus peel pectin and alginate-based emulgel particles for small intestine-targeted oral delivery of curcumin.

Polysaccharides are a prominent choice in the realm of food-grade oral delivery systems due to their resistance to degradation by digestive enzymes in the oral, gastric, and small intestinal environments, as well as their ease of production, cost-effectiveness, and potential health benefits as prebiotics. Furthermore, their ability to respond to pH-induced dissolution, along with their emulsifying properties, can be strategically employed to achieve precise targeting of lipophilic bioactives to the small intestine. In this study, citrus peel pectin and alginate served as stabilizers for emulgel particles without supplementary emulsifiers or gelling agents. Within this system, pectin functioned as an emulsifier, while alginate acted as a gelling agent, facilitated by Ca2+-induced ionic crosslinking. The synergistic interplay between pectin and alginate efficiently protected curcumin in gastric conditions and controlled dissolution in the small intestine, depending on the pectin/alginate ratio. These controlled phenomena facilitated lipolysis, curcumin release, and ultimately enhanced curcumin bioaccessibility. Furthermore, once the emulgel particle released all the entrapped curcumin in the small intestine, residual polysaccharides underwent facile degradation by pectinase and alginate lyase, yielding fermentable monosaccharides. This confirms the potential of the emulgel particles for use as a prebiotic in the colon. These findings offer significant promise for enhancing the systematic design of food-grade delivery systems that encapsulate lipophilic bioactives, achieving controlled release, enhanced stability, and improved bioaccessibility. Importantly, this system can comprise components that undergo complete digestion, absorption, and utilization in the human body, encompassing materials such as oil, nutraceuticals, and prebiotics, all without presenting health risks.

Therapeutic effect and metabolic fingerprinting of triple-negative breast cancer cells following exposure to a novel pH-responsive, gambogic acid-loaded micelle.

Triple-negative breast cancer (TNBC) is a subtype of breast cancer with a poor prognosis and lacks effective therapeutic targets. The use of gambogic acid (GA), a class of active ingredients in traditional Chinese medicine with anti-tumour potential, is limited in tumour therapy owing to its drawbacks and unclear organ toxicity. In this study, we used the pH-responsive amphiphilic block copolymer, PEOz-PCL, to create nanodrugs for GA delivery to MDA-MB-231 cells. The pH-responsive GA-loaded micelles were prepared through nanoprecipitation with a more homogeneous size. The average particle size was 42.29 ± 1.74 nm, and the zeta potential value was 9.88 ± 0.17 mV. The encapsulation rate was 85.06%, and the drug loading rate was 10.63%. The process was reproducible, and sustained release reached 80% in 96 h at acid pH 5.0. Furthermore, cellular tests using CCK-8, TUNEL, and flow cytometry revealed that pH-responsive GA-loaded micelles killed MDA-MB-231 cells more effectively and had much higher activity and targeting compared with free drugs. Metabolomic analysis of the changes in differential metabolites revealed that pH-responsive GA-loaded micelles may inhibit TNBC cells by causing amino acid anabolism, nucleotide metabolism, and glucose metabolism, as well as by affecting their energy sources. The study outcomes will help understand the mechanism of action and the therapeutic efficacy of pH-responsive GA-loaded micellesin vivo.

Cell Membrane Coated pH-Responsive Intelligent Bionic Delivery Nanoplatform for Active Targeting in Photothermal Therapy.

Aim: To produce pH-responsive bionic high photothermal conversion nanoparticles actively targeting tumors for sensitizing photothermal therapy (PTT). Materials and Methods: The bionic nanoparticles (ICG-PEI@HM NPs) were prepared by electrostatic adsorption of indocyanine green (ICG) coupled to polyethyleneimine (PEI) and modified with tumor cell membranes. In vitro and in vivo experiments were conducted to investigate the efficacy of ICG-PEI@HM-mediated PTT. Results: The intelligent responsiveness of ICG-PEI@HM to pH promoted the accumulation of ICG and enhanced the PTT performance of ICG-PEI@HM NPs. Compared with free ICG, NPs exhibited great photothermal stability, cellular uptake, and active tumor targeting for PTT. Conclusion: ICG-PEI@HM NPs can enhance the efficacy of PTT and can be used as a new strategy for the construction of photothermal agents.

pH-Responsive Injectable Multifunctional Pluronic F127/Gelatin-Based Hydrogels with Hydrogen Production for Treating Diabetic Wounds.

Diabetic chronic wounds remain a major clinical challenge with long-term inflammatory responses and extreme oxidative damage. Hence, a pH-responsive injectable multifunctional hydrogel [Gel/CUR-FCHO/Mg (GCM) micromotors] via a Schiff base reaction between gelatin and benzaldehyde-grafted Pluronic F127 drug-loaded micelles (FCHO) was fabricated for the first time. Dynamic Schiff base linkage endowed the GCM hydrogel with the ability to be self-healing, injectable, and pH-responsive for on-demand drug delivery at the wound site. Curcumin (CUR), a hydrophobic drug with antioxidative, anti-inflammatory, and antibacterial activities, was encapsulated into the hydrogel matrix by micellization (CUR-FCHO micelles). Simultaneously, magnesium-based micromotors (Mg micromotors) were physically entrapped into the system for providing active hydrogen (H2) to scavenge reactive oxygen species and alleviate inflammatory responses. As a result, the GCM micromotor hydrogel displayed an inherent antibacterial property, extraordinary antioxidative performance, and remarkable biocompatibility. In the diabetic mouse with a full-thickness cutaneous defect wound, the GCM hydrogel could remodel the inflammatory microenvironment and stimulate vascularization and collagen deposition, thereby facilitating wound closure and enhancing tissue regeneration, which offered a promising therapeutic option for diabetic chronic wound management.

A comparison study between doxorubicin and curcumin co-administration and co-loading in a smart niosomal formulation for MCF-7 breast cancer therapy.

Chemotherapy agents often exhibit limited effectiveness due to their fast elimination from the body and non-targeted delivery. Emerging nanomaterials as drug delivery carriers open new expectancy to overcome these limitations in current chemotherapeutic treatments. In this study, we introduce and evaluate a smart pH-responsive niosomal formulation capable of delivering Doxorubicin (DOX) and Curcumin (CUR) in both individually and co-loaded forms. In particular, drug-loaded niosomes were prepared using thin-film hydration method and then characterized via different physicochemical analyses. The pH responsivity of the carrier was assessed by performing a drug release study in three different pH conditions (4, 6.5, and 7.4). Finally, the anticancer efficacy of the therapeutic compounds was evaluated through the MTT assay. Our results showed spherical particles with a size of about 200 nm and -2 mV surface charge. Encapsulation efficiency (EE%) of the nanocarrier was about 77.06 % and 79.08 % for DOX and CUR, respectively. The release study confirmed the pH responsivity of the carrier. The MTT assay results revealed about 39 % and 43 % of cell deaths after treatment with cur-loaded and dox-loaded niosomes, which increased to 74 % and 79 % after co-administration and co-loading forms of drugs, respectively, exhibiting increased anticancer efficacy by selectively delivering DOX and CUR individually or in combination. Overall, these findings suggest that our nanoformulation holds the potential as a targeted and highly effective approach for cancer management and therapy, overcoming the limitations of conventional chemotherapy drugs.

Oxidation-Resistant Silicon Nanosystem for Intelligent Controlled Ferrous Foliar Delivery to Crops.

Since ferrous (Fe(II)) is the main form of plant absorption, traditional ferrous foliar fertilizers (TFFF) are widely used in modern agriculture. However, TFFF suffer from the shortcomings of weak antioxidant capacity (AC), low foliar adhesion efficiency (FAE), poor fertilizer utilization efficiency (FUE), and noncontrollable slow-release behavior. To overcome these limitations, an oxidation-resistant silicon nanosystem for intelligent controlled ferrous foliar delivery to crops was first developed by using environmentally friendly micro/nano structured hollow silicon as carrier, and combining with vitamin C (in situ antioxidant) to synthesize an oxidation-resistant ferrous foliar fertilizer (ORFFF) for ameliorating Fe-deficiency in crops and increasing crop yield. Compared with TFFF, the ORFFF has excellent ferrous AC (only 11.5% of Fe(II) was oxidized in ORFFF within 72 h), ultrahigh FAE (∼84% of adhesion percentage (%) after two-times simulated rain rinsing), nutrient slow-release ability (720 h gradually release 100.6 mg·g-1), pH-controlled release ability (pH 3-8), and verified high biological safety (100% survival rate for zebrafish and earthworm). The pot experiments showed that ORFFF can correct the Fe-deficiency symptoms of tomato seedlings promptly compared with TFFF, and the FUE of ORFFF is 4.2 times that of TFFF. The specific pH responsiveness of ORFFF can control the slow-release rate of Fe(II) to satisfy the needs of Fe in varying crops and different growing periods of crops. This work provides a feasible way to achieve green and safe Fe supplementation for crops, reduce Fe fertilizer waste, avoid soil pollution caused by Fe fertilizer abuse, and promote the sustainable development of modern nanoagriculture.

Green Nanopesticide: pH-Responsive Eco-Friendly Pillar[5]arene-Modified Selenium Nanoparticles for Smart Delivery of Carbendazim to Suppress Sclerotinia Diseases.

Controlled-release delivery systems have been widely used to improve the efficacy and bioavailability of pesticides and minimize environmental risks. Herein, a fungicide carbendazim (CBZ)-loaded, a kind of nanovalve including trimethylammoniumpillar[5]arene (AP5), and methyl orange (MO)-functionalized mesoporous selenium (MSe) nanopesticides (CBZ@AP5/MSe⊃MO) were prepared. The nanovalve endowed CBZ@AP5/MSe⊃MO with a pH-responsive property, so the CBZ@AP5/MSe⊃MO can respond to the microenvironment of the pathogen Sclerotinia sclerotiorum (S. sclerotiorum). First, MO was shed due to protonation, and AP5-functionalized MSe gradually dissolved in an acid environment. Finally, CBZ was released rapidly. It is reported that AP5 and MO as the host and guest functionalized mesoporous selenium (MSe) have never been applied to agriculture. In vitro release experiments showed that the cumulative release rate of CBZ at pH 4.5 was 1.74 times higher than that in a neutral environment. In addition, we found that the contact angle of the CBZ@AP5/MSe⊃MO in maize and rape leaves was effectively decreased, which could retain more in the leaves after washout. It can also decrease the dry biomass and the reducing sugar of S.sclerotiorum. The CBZ@AP5/MSe⊃MO holds a good safety profile for plants, animal cells, and the environment owing to the targeted release properties. These results suggest that CBZ@AP5/MSe⊃MO is an environmentally friendly and effective drug-loaded system against S. sclerotiorum. It provides a new strategy for the design and development of nanopesticides and the control of S. sclerotiorum.

pH-Responsive and Recyclable Hydrogels for Gas Releasing and Scavenging.

Gas-releasing/scavenging hydrogels have wide applications in biomedical and industrial fields. However, the covalently crosslinked nature of these existing materials makes them difficult to degrade or recycle, leading to a waste of raw materials and aggravating environmental pollution. Herein, a new class of pH-responsive and recyclable hydrogels with versatile gas-releasing and scavenging properties is reported, utilizing pH changes to reversibly control disassembly and reassembly of the hydrogel network. The initial hydrogels are constructed via the one-pot radical polymerization and contain dynamic molecular networks based on hydrophobic interactions, which can disassemble when the materials are placed in low pH solutions. The disassembled copolymer chains can reform hydrogels, following supplementation with fresh mineral salts and micelle monomers in neutral solutions. Moreover, the mineral salts used to reform hydrogels can function as gas donors or scavengers, endowing these hydrogels with versatile gas-releasing and consuming properties. Overall, this research provides a facile and environmentally friendly method to recycle hydrogels with gas-releasing and gas-scavenging properties, which have potential applications in diverse fields, including wound healing, wastewater management, and gas therapy for diseases.

A pH-responsive metal-organic framework for the co-delivery of HIF-2α siRNA and curcumin for enhanced therapy of osteoarthritis.

The occurrence of osteoarthritis (OA) is highly correlated with the reduction of joint lubrication performance, in which persistent excessive inflammation and irreversible destruction of cartilage dominate the mechanism. The inadequate response to monotherapy methods, suboptimal efficacy caused by undesirable bioavailability, short retention, and lack of stimulus-responsiveness, are few unresolved issues. Herein, we report a pH-responsive metal-organic framework (MOF), namely, MIL-101-NH2, for the co-delivery of anti-inflammatory drug curcumin (CCM) and small interfering RNA (siRNA) for hypoxia inducible factor (HIF-2α). CCM and siRNA were loaded via encapsulation and surface coordination ability of MIL-101-NH2. Our vitro tests showed that MIL-101-NH2 protected siRNA from nuclease degradation by lysosomal escape. The pH-responsive MIL-101-NH2 gradually collapsed in an acidic OA microenvironment to release the CCM payloads to down-regulate the level of pro-inflammatory cytokines, and to release the siRNA payloads to cleave the target HIF-2α mRNA for gene-silencing therapy, ultimately exhibiting the synergetic therapeutic efficacy by silencing HIF-2α genes accompanied by inhibiting the inflammation response and cartilage degeneration of OA. The hybrid material reported herein exhibited promising potential performance for OA therapy as supported by both in vitro and in vivo studies and may offer an efficacious therapeutic strategy for OA utilizing MOFs as host materials.

pH-responsive in situ gelling properties of thiolated citrus high-methoxyl pectin and its potential gel mechanism.

pH-responsive in situ gelling properties of thiolated citrus high-methoxyl pectin (TCHMP) were investigated in this study. The gelation capacity results revealed that the in situ gelation behavior of TCHMP only occurred when the pH value was higher than 6.25. The gel strength increased from 26.63 g to 42.77 g as the pH value increased from 7.4 to 8.9. Rheological measurements confirmed that the apparent viscosity and viscoelasticity of TCHMP were highly dependent on pH value and dialysis time. Compared with the control group, the apparent viscosity of TCHMP dialyzed in phosphate-buffered saline (PBS) of pH 8.9 for 180 min increased 695-fold. During the dialysis process of TCHMP at different pH values (7.4-8.9), the final thiol groups content decreased and the final disulfide bonds content increased with the increase in pH value. This illustrates that the mechanism of in situ gelation is mainly the oxidation of thiol-thiol groups to form disulfide bonds. These results can put forward new insights into the pH-responsive in situ gelling properties of TCHMP and provide a theoretical basis for the application of TCHMP in neutral and alkaline gel systems.

pH-Responsive Selenium Nanoplatform for Highly Efficient Cancer Starvation Therapy by Atorvastatin Delivery.

Recently, starvation-inducing nutrient deprivation has been regarded as a promising strategy for tumor suppression. As a first-line lipid-lowering drug, atorvastatin (ATV) significantly reduces caloric intake, suggesting its potential in starvation therapy for suppressing tumors. Accordingly, we developed a novel starvation therapy agent (HA-Se-ATV) in this study to suppress tumor growth by using hyaluronic acid (HA)-conjugated chitosan polymer-coated nano-selenium (Se) for loading ATV. HA-Se-ATV targets cancer cells, following which it effectively accumulates in the tumor tissue. The HA-Se-ATV nanoplatform was then activated by inducing a weakly acidic tumor microenvironment and subsequently releasing ATV. ATV and Se synergistically downregulate the levels of cellular adenosine triphosphate while inhibiting the expression of thioredoxin reductase 1. Consequently, the starvation-stress reaction of cancer cells is significantly elevated, leading to cancer cell death. Furthermore, the in vivo results indicate that HA-Se-ATV effectively suppresses tumor growth with a low level of toxicity, demonstrating its great potential for clinical translation.

Intelligent films based on pectin, sodium alginate, cellulose nanocrystals, and anthocyanins for monitoring food freshness.

To address consumer-level food waste, and pollution from commercial plastics, we developed intelligent films using sodium alginate (SA), pectin (PC), cellulose nanocrystals (CNCs), and anthocyanins extracted from red cabbage (RCA). We also investigated two methods of reinforcing these films - cross-linking (CL), and the addition of CNCs. Both together and separately, these methods improved SA/PC films' mechanical properties and thermal stability. The optimal SA/PC/CNCs/RCA/CL films exhibited pH-dependent color-response properties and high water resistance. These were then tested as colorimetric freshness indicators for shrimp samples, both through seepage and the monitoring of volatile compounds. The colors of the indicators changed from lilac to dark green to greenish-yellow after storage at 25 °C for 72 h, whereas at 4 °C, they changed much more slowly over the same time period. This demonstrated the excellent potential of such films to reduce food waste by providing real-time warnings of pH variation resulting from spoilage.

Development of chitosan/halloysite/graphitic­carbon nitride nanovehicle for targeted delivery of quercetin to enhance its limitation in cancer therapy: An in vitro cytotoxicity against MCF-7 cells.

Although quercetin (QC) has valuable advantages, its low water solubility and poor permeability have limited its utilization as an anticancer drug. In this study, hydrogel nanocomposite of chitosan (CS), halloysite (HNT), and graphitic­carbon nitride (g-C3N4) was prepared and loaded by QC using a water in oil in water emulsification process to attain QC sustained-release. Using g-C3N4 in the HNT/CS hydrogel solution enhanced the entrapment effectiveness (EE %) by up to 86 %. The interactions between QC and nanoparticles caused the nanocomposite pH-responsive behavior that assists in minimizing the side effect of the anticancer agent by controlling the burst release of QC at neutral conditions. According to DLS analysis, the size of the QC-loaded nanovehicle was 454.65 nm, showing that nanoparticles are highly monodispersed, which also was approved by FE-SEM. Additionally, Zeta potential value for the fabricated drug-loaded nanocarrier is +55.23 mV displaying that nanoparticles have good stability. The hydrogel nanocomposite structure's completeness was shown by FTIR pattern, and quercetin was included into the designed delivery system based on XRD data. Besides, the drug release profile indicated that a targeted sustained-release and pH-sensitive release of anticancer drug with the 96-hour extended-release were noticed. In order to comprehend the process of QC release at pH 5.4 and 7.4, four kinetic models were employed to find the best-suited model according to the acquired release data. Finally, the MTT experiment revealed considerable cytotoxicity against breast cancer cells, MCF-7 cell line was experimented in vitro, for the CS/HNT/g-C3N4 targeted delivery system in comparison to QC as a free drug. According to the above description, the CS/HNT/g-C3N4 delivery platform is a unique pH-sensitive drug delivery system for anticancer purposes that improves loading as well as sustained-release of quercetin.

Development of pH-responsive active film materials based on purple corncob and its application in meat freshness monitoring.

The use of petroleum-based food packaging materials is causing environmental damage and increasing greenhouse gas production. Consequently, there is a great interest in developing smart and sustainable alternative materials. In this study, an agricultural waste product (purple corncob extract, PCCE) was used as a raw material to prepare environmentally friendly pH-sensitive packaging materials. Natural pH-sensitive pigments (anthocyanins) and lignin-containing cellulose nanocrystals (LCNC) were extracted from the purple corncobs. A cationic biopolymer (chitosan) was used as a scaffolding material to assemble the film matrix. Composite film (LCNC-PCCE-chitosan) was produced using a simple solvent casting method. Fourier transform infrared spectroscopy and scanning electron microscopy analyses showed that the PCCE and LCNC were well dispersed within the chitosan matrix and they interacted with the matrix through hydrogen bonding and electrostatic interactions. The addition of LCNC improved the hydrophobicity and mechanical properties of the film and imparted antioxidant activity and UV-blocking properties. The presence of anthocyanins in the PCCE endowed the film with a sensitive and reversible pH response, which could be well used to monitor changes in the freshness of pork and shrimp products.

Preparation and characterization of long-term antibacterial and pH-responsive Polylactic acid/Octenyl succinic anhydride-chitosan @ tea tree oil microcapsules.

Encapsulation technology can increase the stability and maintain the volatile active substances of plant essential oils. In the present study, tree essential oil (TTO) was encapsulated with polylactic acid (PLA) modified by octenyl succinic anhydride chitosan (OSA-CS) as shell materials to form long-term antibacterial and pH-responsive microcapsules. The PLA/OSA-CS@TTO microcapsules were characterized by high performance liquid chromatography (HPLC), scanning electron microscopy (SEM) and antibacterial performance testing. The results showed that the average particle size of microcapsules was 10 µm, and the encapsulation efficiency and drug loading efficiency of TTO reached 81.5 % and 60.3 %. After 4800 min of release in media at different pH (5 and 7) still sequestered 55.32 % and 56.74 % of TTO which approved the shell of microcapsules responded to different pH values. The microcapsules remained stable for 80 days after drying, and preserving 39.7 % of the core material. The morphology of PLA/OSA-CS@TTO microcapsules revealed that the PLA/OSA-CS@TTO microcapsules presented smooth and firm structure. Antibacterial test for staphylococcus aureus of those microcapsules implied that the bacteriostatic rate reached 100 % after 72 h. Bio-based macromolecular modification strategies can provide inspiration for the development of green microcapsules.

Rod-like hybrid nanomaterial with tumor targeting and pH-responsive for cancer chemo/photothermal synergistic therapy.

The development of chemo/photothermal nanotherapeutic systems with excellent photothermal performance, stable drug loading, tumor targeting and strong membrane penetration still remains a challenge. To address this problem, herein a rod-like nanocomposite system (AuNR@FA-PR/PEG) forming from folic acid (FA) terminated carboxylated cyclodextrin (CD) pseudopolyrotaxane (FA-PR) and polyethylene glycol (PEG) modifying gold nanorods (AuNR) was reported. Cisplatin (CDDP) was loaded in AuNR@FA-PR/PEG via coordination bonds to prepare a rod-like pH-responsive nanosystem (AuNR@FA-PR/PEG/CDDP) with chemotherapy/photothermal therapy. The rod-like morphology of AuNR@FA-PR/PEG was characterized by transmission electron microscope. In vitro drug release experiments showed the pH-responsive of AuNR@FA-PR/PEG/CDDP. In vivo real-time imaging assays proved AuNR@FA-PR/PEG/CDDP could rapidly enrich in the tumor area and stay for a long time because of folate targeting and their rod-like morphology. In vivo photothermal imaging assays showed AuNR@FA-PR/PEG/CDDP excellent photothermal performance, the average temperature of tumor region could reach 63.5 °C after 10 min irradiation. In vitro and in vivo experiments also demonstrated that the combined therapy of chemotherapy and photothermal therapy had an outstandingly synergistic effect and improved the therapeutic efficacy comparing with chemotherapy and photothermal therapy alone. Therefore, the prepared rod-like AuNR@FA-PR/PEG/CDDP will provide a new strategy for the effective treatment of cancer.

Self-assembled hydrogel nanocube for stimuli responsive drug delivery and tumor ablation by phototherapy against breast cancer.

The shape and responsiveness of nanoengineered delivery carriers are crucial characteristics for the rapid and efficient delivery of therapeutics. We report on a novel type of micrometer-sized hydrogel particles of controlled shape with dual pH and redox sensitivity for intracellular delivery of anticancer drugs and phototherapy. The cubical HA-DOP-CS-PEG networks with disulfide links are obtained by cross-linking HA-DOP-CS-PEG with cystamine. The pH-triggered hydrogel swelling/shrinkage was not only affords effective doxorubicin release. It also actively provides the endosomal/lysosomal escape, redox-triggered drug release. The hydrogels degrade rapidly to low molecular weight chains in the presence of the typical intracellular concentration of glutathione. Drug-loaded cube particles found to be 12% more cytotoxic. ICG and DOX-loaded hydrogel cubes demonstrate 90% cytotoxicity when incubated with MCF-7 cancer cells for 24 and 48 h, respectively. This approach integrates the advantages of pH sensitivity, enzymatic degradation, and shape-regulated internalization for novel types of "intelligent" three-dimensional networks with programmable behavior for controlled delivery of therapeutics.

pH-Triggered Size-Tunable Silver Nanoparticles: Targeted Aggregation for Effective Bacterial Infection Therapy.

The rapid spread of drug-resistant pathogens threatens human health. To address the current antibacterial dilemma, the development of antibiotic-free strategies using nanotechnology is imperative. In this study, silver nanoparticles (Ag-P&C NPs) with pH-sensitive charge reversal and self-aggregation capacities are successfully synthesized. In the acidic microenvironment of bacterial biofilms, protonation of the surface peptide enhances the affinity of Ag-P&C NPs for bacteria, which can make Ag-P&C NPs prone to target and penetrate into biofilms, and the self-aggregated capacity helps Ag-P&C NPs remain in biofilms for a long time to disrupt bacterial biofilm formation. In addition, biocompatible Ag-P&C NPs are utilized in three types of bacteria-infected animal models. They exhibit an excellent performance in killing bacteria, inhibiting plaque biofilms, and ameliorating inflammatory responses. In conclusion, this study offers new insights into antibiotic-free antibacterial strategies, and exhibits promising application prospects.