Edge interface microenvironment regulation of CoOOH/commercial activated carbon nano-hybrids enabling PMS activation for degrading ciprofloxacin

Peroxymonosulfate (PMS) is widely employed to generate oxygen-containing reactive species for ciprofloxacin (CIP) degradation. Herein, cobalt oxyhydroxide @activated carbon (CoOOH@AC) was synthesized via a wet chemical sedimentation method to activate PMS for degradation of CIP. The result suggested AC can support the vertical growth of CoOOH nanosheets to expose high-activity Co-contained edges, possessing efficient PMS activation and degradation activity and catalytic stability. In the presence of 3.0 mg of optimal CoOOH@AC and 2 mM PMS, 96.8 % of CIP was degraded within 10 min, approximately 11.6 and 9.97 times greater than those of CoOOH/PMS and AC/PMS systems. Notably, it was disclosed that the optimal CoOOH@AC/PMS system still exhibited efficient catalytic performance in a wide pH range, different organics and common co-existing ions. Quenching experiments and electron paramagnetic resonance indicated that both radical and non-radical processes contributed to the degradation of CIP, with 1O2 and direct electron transfer accounting for the non-radical pathway and SO4•- and •OH serving as the main radical active species. Finally, possible CIP degradation pathways were proposed based on high-performance liquid chromatography-mass spectrometry. This study provided an alternate method for wastewater treatment based on PMS catalyzed by cobalt-based hydroxide.

Degradable Nanogels Based on Poly[Oligo(Ethylene Glycol) Methacrylate] (POEGMA) Derivatives through Thermo-Induced Aggregation of Polymer Chain and Subsequent Chemical Crosslinking

Polymer nanogels-considered as nanoscale hydrogel particles-are attractive for biological and biomedical applications due to their unique physicochemical flexibility. However, the aggregation or accumulation of nanoparticles in the body or the occurrence of the body's defense reactions still pose a research challenge. Here, we demonstrate the fabrication of degradable nanogels using thermoresponsive, cytocompatible poly[oligo(ethylene glycol) methacrylate]s-based copolymers (POEGMA). The combination of POEGMA's beneficial properties (switchable affinity to water, nontoxicity, non-immunogenicity) along with the possibility of nanogel degradation constitute an important approach from a biological point of view. The copolymers of oligo(ethylene glycol) methacrylates were partially modified with short segments of degradable oligo(lactic acid) (OLA) terminated with the acrylate group. Under the influence of temperature, copolymers formed self-assembled nanoparticles, so-called mesoglobules, with sizes of 140-1000 nm. The thermoresponsive behavior of the obtained copolymers and the nanostructure sizes depended on the heating rate and the presence of salts in the aqueous media. The obtained mesoglobules were stabilized by chemical crosslinking via thiol-acrylate Michael addition, leading to nanogels that degraded over time in water, as indicated by the DLS, cryo-TEM, and AFM measurements. Combining these findings with the lack of toxicity of the obtained systems towards human fibroblasts indicates their application potential.

Cancer chemotherapy resistance: Mechanisms and recent breakthrough in targeted drug delivery

Conventional chemotherapy, one of the most widely used cancer treatment methods, has serious side effects, and usually results in cancer treatment failure. Drug resistance is one of the primary reasons for this failure. The most significant drawbacks of systemic chemotherapy are rapid clearance from the circulation, the drug's low concentration in the tumor site, and considerable adverse effects outside the tumor. Several ways have been developed to boost neoplasm treatment efficacy and overcome medication resistance. In recent years, targeted drug delivery has become an essential therapeutic application. As more mechanisms of tumor treatment resistance are discovered, nanoparticles (NPs) are designed to target these pathways. Therefore, understanding the limitations and challenges of this technology is critical for nanocarrier evaluation. Nano-drugs have been increasingly employed in medicine, incorporating therapeutic applications for more precise and effective tumor diagnosis, therapy, and targeting. Many benefits of NP-based drug delivery systems in cancer treatment have been proven, including good pharmacokinetics, tumor cell-specific targeting, decreased side effects, and lessened drug resistance. As more mechanisms of tumor treatment resistance are discovered, NPs are designed to target these pathways. At the moment, this innovative technology has the potential to bring fresh insights into cancer therapy. Therefore, understanding the limitations and challenges of this technology is critical for nanocarrier evaluation.

Pheophorbide-a as a Light-Triggered Liposomal Switch: For the Controlled Release of Alpinia galanga (A. galanga) Essential Oil and Its Stability, Antioxidant, and Antibacterial Activity Assessment

In this study, Alpinia galanga essential oil liposomes (EO-Lip) were prepared with soybean lecithin and cholesterol as wall materials. A light-responsive liposome (EO-PLip) was designed for the controlled release of A. galanga oil based on the light-responsive properties of Pheophorbide-a. The dependence of Pheophorbide-a on illumination time was proved by UV spectroscopy. Characterization techniques such as UV spectroscopy, transmission electron microscopy, and Fourier transform infrared spectroscopy demonstrated that the essential oils were successfully encapsulated in liposomes. Moreover, the particle size of EO-PLip was 166.30 nm, the polydispersity index was 0.22, the zeta potential was -49.50 mV, and the encapsulation efficiency was 30.83%. Both EO-Lip and EO-Plip have high sustained-release effects on essential oil and showed light-responsive release characteristics under infrared stimulation. The prepared liposomes had good storage stability at 4 °C for 28 d. EO-PLip showed excellent transient antioxidant and bacteriostatic properties based on the ability to respond to light and slow release. This EO-PLip provided a platform for essential oils and might be used as a potent and controllable solution.

Highly Efficient and Simultaneous Removal of Cr(VI) and Imidacloprid through a Ferrocene-Modified MIL-100(Fe) Composite from an Aqueous Solution

A novel nanocomposite [Fc-MIL-100(Fe)] was constructed by combining ferrocene (Fc) with the porous structural metal-organic framework [MIL-100(Fe)]. The proposed composite material could simultaneously and efficiently remove hexavalent chromium [Cr(VI)] and imidacloprid and reduced strongly noxious Cr(VI) to weakly noxious trivalent chromium [Cr(III)]. The removal efficiencies of the composite material for Cr(VI) and imidacloprid could reach 95% after 15 h. The adsorption process was determined by kinetics, isotherms, and thermodynamics. The results demonstrated that the adsorption kinetics of Cr(VI) followed the pseudo-second-order model mainly by chemisorption; meanwhile, the adsorption of imidacloprid by the material conformed to the pseudo-first-order kinetics, which indicated that physical adsorption was the main process. Additionally, the intraparticle diffusion model revealed that the uptake of imidacloprid and Cr(VI) occurred via intraparticle diffusion at the composite material. The adsorption procedure for Cr(VI) was fitted to the Langmuir model (R² = 0.995) via monolayer adsorption, and that for imidacloprid was fitted to the Freundlich model (R² = 0.995) due to multilayer or heterogeneous adsorption. The thermodynamic research confirmed that the adsorption procedure was exothermic and spontaneous. Infrared spectroscopy, X-ray photoelectron spectra, and the pH effect implied that intermolecular hydrogen bonding and electrostatic interaction played a crucial role during the removal process. Fc-MIL-100(Fe) also exhibited long-term stability and satisfactory regeneration and reusability. Therefore, this method may enhance an environmentally friendly and prospective approach for concurrently removing imidacloprid and Cr(VI) from wastewater.

Temperature and Photo Dual-Stimuli Responsive Block Copolymer Self-Assembly Micelles for Cellular Controlled Drug Release

To well adapt to the complicated physiological environments, it is necessary to engineer dual- and/or multi-stimuli responsive drug carriers for more effective drug release. For this, a novel temperature responsive lateral chain photosensitive block copolymer, poly[(N-isopropylacrylamide-co-N,N-dimethylacrylamide) -block-propyleneacylalkyl-4-azobenzoate] (P(NIPAM-co-DMAA)-b-PAzoHPA), is synthesized by atom transfer radical polymerization. The structure is characterized by ¹ H nuclear magnetic resonance spectrometry and laser light scattering gel chromatography system. The self-assembly behavior, morphology, and sizes of micelles are investigated by fluorescence spectroscopy, transmission electron microscope, and laser particle analyzer. Dual responsiveness to light and temperature is explored by ultraviolet-visible absorption spectroscopy. The results show that the copolymer micelles take on apparent light and temperature dual responsiveness, and its lower critical solution temperature (LCST) is above 37 °C, and changes with the trans-/cis- isomerization of azobenzene structure under UV irradiation. The blank copolymers are nontoxic, whereas the paclitaxel (PTX)-loaded counterparts possessed comparable anticancer activities to free PTX, with entrapment efficiency of 83.7%. The PTX release from the PTX-loaded micelles can be mediated by changing temperature and/or light stimuli. The developed block copolymers can potentially be used for cancer therapy as drug controlled release carriers.

Stimuli-Responsive Aliphatic Polycarbonate Nanocarriers for Tumor-Targeted Drug Delivery

Nanoparticles based on amphiphilic copolymers with tunable physicochemical properties can be used to encapsulate delicate pharmaceutics while at the same time improving their solubility, stability, pharmacokinetic properties, reducing immune surveillance, or achieving tumor-targeting ability. Those nanocarriers based on biodegradable aliphatic polycarbonates are a particularly promising platform for drug delivery due to flexibility in the design and synthesis of appropriate monomers and copolymers. Current studies in this field focus on the design and the synthesis of new effective carriers of hydrophobic drugs and their release in a controlled manner by exogenous or endogenous factors in tumor-specific regions. Reactive groups present in aliphatic carbonate copolymers, undergo a reaction under the action of a stimulus: e.g., acidic hydrolysis, oxidation, reduction, etc. leading to changes in the morphology of nanoparticles. This allows the release of the drug in a highly controlled manner and induces a desired therapeutic outcome without damaging healthy tissues. The presented review summarizes the current advances in chemistry and methods for designing stimuli-responsive nanocarriers based on aliphatic polycarbonates for controlled drug delivery.

Remote Light-Responsive Nanocarriers for Controlled Drug Delivery: Advances and Perspectives

Engineering of smart photoactivated nanomaterials for targeted drug delivery systems (DDS) has recently attracted considerable research interest as light enables precise and accurate controlled release of drug molecules in specific diseased cells and/or tissues in a highly spatial and temporal manner. In general, the development of appropriate light-triggered DDS relies on processes of photolysis, photoisomerization, photo-cross-linking/un-cross-linking, and photoreduction, which are normally sensitive to ultraviolet (UV) or visible (Vis) light irradiation. Considering the issues of poor tissue penetration and high phototoxicity of these high-energy photons of UV/Vis light, recently nanocarriers have been developed based on light-response to low-energy photon irradiation, in particular for the light wavelengths located in the near infrared (NIR) range. NIR light-triggered drug release systems are normally achieved by using two-photon absorption and photon upconversion processes. Herein, recent advances of light-responsive nanoplatforms for controlled drug release are reviewed, covering the mechanism of light responsive small molecules and polymers, UV and Vis light responsive nanocarriers, and NIR light responsive nanocarriers. NIR-light triggered drug delivery by two-photon excitation and upconversion luminescence strategies is also included. In addition, the challenges and future perspectives for the development of light triggered DDS are highlighted.

The light-controlling of temperature-responsivity in stimuli-responsive polymers

Light-controlling of phase separation in temperature-responsive polymer solutions by using light-responsive materials for reversible controlling physical and chemical properties of the media with an out-of-system stimulus with tunable intensity.

Polycarbonate-based core-crosslinked redox-responsive nanoparticles for targeted delivery of anticancer drug

We reported a facile and efficient strategy for the construction of polycarbonate-based core-crosslinked redox-responsive nanoparticles (CC-RRNs), which can efficiently regulate the drug loading content and redox-responsive drug release. A series of CC-RRNs for delivery of doxorubicin (DOX) were synthesized by the click reaction between alkyne-bearing amphiphilic block copolymer PEG-b-poly(MPC)_n (PMPC) and azide-terminated α-lipoic acid derivative (LA) and 6-bromohexanoic acid derivative (AHE) at different ratios, followed by introduction of crosslinked networks under a catalytic amount of dithiothreitol (DTT). Dynamic light scattering (DLS) experiments showed that the CC-RRNs presented more excellent stability over non-crosslinked unresponsive nanoparticles (NC-URNs) under physiological conditions. Interestingly, the DOX loading content of nanoparticles (NPs) increased as the proportion of LA moieties increased, and the maximum value was up to 20.0 ± 0.6%, close to the theoretical value of 23.1%. The in vitro redox-responsive release of DOX and MTT assays confirmed that the ratio of LA-to-AHE of PMPC-based polymers not only determined the ultimate drug release of DOX-loaded CC-RRNs in a reductive environment, but also dominated the cytotoxicity towards HepG2 cells. Confocal laser scanning microscopy (CLMS) and flow cytometry further proved the enhancement of cellular uptake and tumor accumulation. This facile strategy overcomes tedious fabrication procedures for drug nanocarriers, offers an opportunity for regulating the functionality of NPs, and thus paves the pathway for scale-up production of biodegradable drug carriers with biocompatibility, stability and targetability.

Nanotechnology for Cancer Therapy Based on Chemotherapy

Chemotherapy has been widely applied in clinics. However, the therapeutic potential of chemotherapy against cancer is seriously dissatisfactory due to the nonspecific drug distribution, multidrug resistance (MDR) and the heterogeneity of cancer. Therefore, combinational therapy based on chemotherapy mediated by nanotechnology, has been the trend in clinical research at present, which can result in a remarkably increased therapeutic efficiency with few side effects to normal tissues. Moreover, to achieve the accurate pre-diagnosis and real-time monitoring for tumor, the research of nano-theranostics, which integrates diagnosis with treatment process, is a promising field in cancer treatment. In this review, the recent studies on combinational therapy based on chemotherapy will be systematically discussed. Furthermore, as a current trend in cancer treatment, advance in theranostic nanoparticles based on chemotherapy will be exemplified briefly. Finally, the present challenges and improvement tips will be presented in combination therapy and nano-theranostics.