Coordinated modulation of long non-coding RNA ASBEL and curcumin co-delivery through multicomponent nanocomplexes for synchronous triple-negative breast cancer theranostics

BACKGROUND

Abnormally regulated long non-coding RNAs (lncRNAs) functions in cancer emphasize their potential to serve as potential targets for cancer therapeutic intervention. LncRNA ASBEL has been identified as oncogene and an anti-sense transcript of tumor-suppressor gene of BTG3 in triple-negative breast cancer (TNBC).

RESULTS

Herein, multicomponent self-assembled polyelectrolyte nanocomplexes (CANPs) based on the polyelectrolytes of bioactive hyaluronic acid (HA) and chitosan hydrochloride (CS) were designed and prepared for the collaborative modulation of oncogenic lncRNA ASBEL with antago3, an oligonucleotide antagonist targeting lncRNA ASBEL and hydrophobic curcumin (Cur) co-delivery for synergetic TNBC therapy. Antago3 and Cur co-incorporated CANPs were achieved via a one-step assembling strategy with the cooperation of noncovalent electrostatic interactions, hydrogen-bonding, and hydrophobic interactions. Moreover, the multicomponent assembled CANPs were ulteriorly decorated with a near-infrared fluorescence (NIRF) Cy-5.5 dye (FCANPs) for synchronous NIRF imaging and therapy monitoring performance. Resultantly, MDA-MB-231 cells proliferation, migration, and invasion were efficiently inhibited, and the highest apoptosis ratio was induced by FCANPs with coordination patterns. At the molecular level, effective regulation of lncRNA ASBEL/BTG3 and synchronous regulation of Bcl-2 and c-Met pathways could be observed.

CONCLUSION

As expected, systemic administration of FCANPs resulted in targeted and preferential accumulation of near-infrared fluorescence signal and Cur in the tumor tissue. More attractively, systemic FCANPs-mediated collaborative modulating lncRNA ASBEL/BTG3 and Cur co-delivery significantly suppressed the MDA-MB-231 xenograft tumor growth, inhibited metastasis and extended survival rate with negligible systemic toxicity. Our present study represented an effective approach to developing a promising theranostic platform for combating TNBC in a combined therapy pattern.

The interplay of signaling pathways and miRNAs in the pathogenesis and targeted therapy of esophageal cancer

Globally, esophageal cancer (EC) is the 6th leading cause of cancer-related deaths and the second deadliest gastrointestinal cancer. Multiple genetic and epigenetic factors, such as microRNAs (miRNAs), influence its onset and progression. miRNAs are short nucleic acid molecules that can regulate multiple cellular processes by regulating gene expression. Therefore, EC initiation, progression, apoptosis evasions, invasion capacity, promotion, angiogenesis, and epithelial-mesenchymal transition (EMT) enhancement are associated with miRNA expression dysregulation. Wnt/-catenin signaling, Mammalian target of rapamycin (mTOR)/P-gp, phosphoinositide-3-kinase (PI3K)/AKT/c-Myc, epidermal growth factor receptor (EGFR), and transforming growth factor (TGF)-β signaling are crucial pathways in EC that are controlled by miRNAs. This review was conducted to provide an up-to-date assessment of the role of microRNAs in EC pathogenesis and their modulatory effects on responses to various EC treatment modalities.

Discovery of endosomalytic cell-penetrating peptides based on bacterial membrane-targeting sequences

Cell-penetrating peptides (CPPs) are prominent scaffolds for drug developments and related research, particularly the endocytic delivery of biomacromolecules. Effective cargo release from endosomes prior to lysosomal degradation is a crucial step, where the rational design and selection of CPPs remains a challenge and calls for deeper mechanistic understandings. Here, we have investigated a strategy of designing CPPs that selectively disrupt endosomal membranes based on bacterial membrane targeting sequences (MTSs). Six synthesized MTS peptides all exhibit cell-penetrating abilities, among which two d-peptides (d-EcMTS and d-TpMTS) are able to escape from endosomes and localize at ER after entering the cell. The utility of this strategy has been demonstrated by the intracellular delivery of green fluorescent protein (GFP). Together, these results suggest that the large pool of bacterial MTSs may be a rich source for the development of novel CPPs.

Vacuolar (H+ )-ATPase subunit c is essential for the survival and systemic RNA interference response in Locusta migratoria

BACKGROUND

Vacuolar (H⁺ )-ATPase (V-ATPase) is a multi-subunit enzyme that hydrolyzes adenosine triphosphate (ATP) to transport protons across a cellular membrane, and it plays an important role in numerous biological processes, including in growth, development and immune responses. The c subunit of V-ATPase is a highly conserved subunit of the rotatory proteolipid ring that is required for binding and transporting protons. To date, there are only a few published reports on V-ATPase-c functions in insects.

RESULTS

We identified and characterized the V-ATPase-c gene in Locusta migratoria, one of the most destructive agricultural insect pests in the world. LmV-ATPase-c was predominately expressed in Malpighian tubules of nymphs, followed by the hindgut and ovary, while the other tissues showed relatively low expression levels. Silencing of LmV-ATPase-c caused severe molting defects in nymphs and a high mortality rate of > 90%. Histological staining and microscopic examination of sections from the abdominal cuticle revealed the absence of newly formed cuticle in nymphs that were injected with dsLmV-ATPase-c. In addition, silencing of LmV-ATPase-c transcript levels significantly impaired RNA interference (RNAi) efficiency of a reporter gene. By quantifying double-stranded RNA (dsRNA) amounts by quantitative polymerase chain reaction (PCR), we found that RNAi against LmV-ATPase-c provoked a dramatic accumulation of dsRNA in the endosomes of epidermal and midgut cells of Locusta migratoria.

CONCLUSION

Our results indicate that LmV-ATPase-c is indispensable for the formation of new cuticle during the molting process and has pivotal functions in dsRNA escape from endosomes. LmV-ATPase-c might be a valuable target for developing new strategies for insect pest management. © 2022 Society of Chemical Industry.

Cetuximab-siRNA Conjugate Linked Through Cationized Gelatin Knocks Down KRAS G12C Mutation in NSCLC Sensitizing the Cells Toward Gefitinib

Delivery of small-interfering RNA (siRNA) has been of great interest in the past decade for effective gene silencing. To overcome synthetic and regulatory challenges posed by nanoparticle-mediated siRNA delivery, antibody–siRNA conjugate (ARC) platform is emerging as a potential siRNA delivery system suitable for clinical translation. Herein, we have developed a delivery technology based on the ARC platform for stable delivery of siRNA called as Gelatin-Antibody Delivery System (GADS). In GADS, positively charged gelatin acts as a linker between antibody–siRNA and enables the endosomal escape of siRNA for gene silencing postcellular internalization. For proof of concept, we synthesized a scalable GADS conjugate comprising of Cetuximab (CTB), cationized gelatin (cGel) and NSCLC KRAS_G12C-specific siRNA. CTB was chemically conjugated to cGel through an amide link to form the CTB–cGel complex. Thereafter, siRNA was chemically conjugated to the cGel moiety of the complex through the thioether link to form CTB–cGel–siRNA conjugate. RP-HPLC analysis was used to monitor the reaction while gel retardation assay was used to determine siRNA loading capacity. SPR analysis showed the preservation of ligand binding affinity of antibody conjugates with K_D of ∼0.3 nM. Furthermore, cellular internalization study using florescent microscopy revealed receptor-mediated endocytosis. The conjugate targeted EGFR receptor of KRAS mutant NSCLC to specifically knockdown G12C mutation. The oncogene knockdown sensitized the cells toward small molecule inhibitor—Gefitinib causing ∼70% loss in cell viability. Western blot analysis revealed significant downregulation for various RAS downstream proteins postoncogene knockdown. Comparison of the efficiency of GADS vis-à-vis positive siRNA control and CRISPR–Cas9-based knockout of KRAS Exon 2 in the NCI-H23 NSCLC cell line suggests GADS as a potential technology for clinical translation of gene therapy.

Nanoparticle mediated RNA delivery for wound healing

Wound healing is a complicated physiological process that comprises various steps, including hemostasis, inflammation, proliferation, and remodeling. The wound healing process is significantly affected by coexisting disease states such as diabetes, immunosuppression, or vascular disease. It can also be impacted by age, repeated injury, or hypertrophic scarring. These comorbidities can affect the rate of wound closure, the quality of wound closure, and tissues' function at the affected sites. There are limited options to improve the rate or quality of wound healing, creating a significant unmet need. Advances in nucleic acid research and the human genome project have developed potential novel approaches to address these outstanding requirements. In particular, the use of microRNA, short hairpin RNA, and silencing RNA is unique in their abilities as key regulators within the physiologic machinery of the cell. Although this innovative therapeutic approach using ribonucleic acid (RNA) is an attractive approach, the application as a therapeutic remains a challenge due to site-specific delivery, off-target effects, and RNA degradation obstacles. An ideal delivery system is essential for successful gene delivery. An ideal delivery system should result in high bioactivity, inhibit rapid dilution, controlled release, allow specific activation timings facilitating physiological stability, and minimize multiple dosages. Currently, these goals can be achieved by inorganic nanoparticle (NP) (e.g., cerium oxide, gold, silica, etc.) based delivery systems. This review focuses on providing insight into the preeminent research carried out on various RNAs and their delivery through NPs for effective wound healing. This article is categorized under: Nanotechnology Approaches to Biology > Nanoscale Systems in Biology Therapeutic Approaches and Drug Discovery > Emerging Technologies Biology-Inspired Nanomaterials > Nucleic Acid-Based Structures.

Polymeric nano-carriers for on-demand delivery of genes via specific responses to stimuli

Polymeric nano-carriers have been developed as a most capable and feasible technology platform for gene therapy. As vehicles, polymeric nano-carriers are obliged to possess high gene loading capability, low immunogenicity, safety, and the ability to transfer various genetic materials into specific sites of target cells to express therapeutic proteins or block a process of gene expression. To this end, various types of polymeric nano-carriers have been prepared to release genes in response to stimuli such as pH, redox, enzymes, light and temperature. These stimulus-responsive nano-carriers exhibit high gene transfection efficiency and low cytotoxicity. In particular, dual- and multi-stimulus-responsive polymeric nano-carriers can respond to a combination of signals. Markedly, these combined responses take place either simultaneously or in a sequential manner. These dual-stimulus-responsive polymeric nano-carriers can control gene delivery with high gene transfection both in vitro and in vivo. In this review paper, we highlight the recent exciting developments in stimulus-responsive polymeric nano-carriers for gene delivery applications.

pH-sensitive small molecule nanodrug self-assembled from amphiphilic vitamin B6-E analogue conjugate for targeted synergistic cancer therapy

To promote the targeted cancer therapy, the pH-sensitive small molecule nanodrug self-assembled from amphiphilic vitamin B6-E analogue conjugate was successfully constructed. Herein, water-soluble vitamin B6 with pKa (5.6) was chemically conjugated to lipid-soluble vitamin E succinate (α-TOS), which showed selective cancer cell killing ability and this amphiphilic small molecule vitamin conjugate could self-assemble to be free nanoparticles (NPs) and doxorubicin-loaded NPs (α-TOS-B6-NPs-DOX). The small molecule nanodrugs could perform the following characteristic: (i) stability in the sodium dodecyl sulfonate (SDS) solution and long-term storage stability in PBS via surface negative charge; (ii) tumor accumulation by enhanced penetration and retention (EPR) effect; (iii) improved cellular internalization by means of vitamin B6 transporting membrane carrier (VTC); and (iv) facilitating endosomal escape and rapid drug release for synergistic toxicity to tumor cells via charge reversal and ester hydrolysis at intracellular pH and/or esterase. Moreover, α-TOS-B6-NPs-DOX exhibited long blood circulation stability and significant tumor accumulation and inhibition with the decreased side effects in vivo. Thus, the pH-sensitive small molecule nanodrug self-assembled from amphiphilic vitamin B6-E analogue conjugate could be the potential drug carriers in targeted synergistic cancer therapy.

Remodeling the tumor microenvironment to improve drug permeation and antitumor effects by co-delivering quercetin and doxorubicin

The tumor microenvironment (TM) plays a critical role in the progress of tumors. However, the TM remodeling effects of currently available therapies remain largely unexplored in many previous reports. In our study, a hyaluronic acid (HA)-modified zeolitic imidazolate framework (ZIF) was successfully fabricated (HA/ZIF) and employed to load doxorubicin (Dox) and quercetin (Que) simultaneously for cancer therapy. The Que and Dox co-loaded HA/ZIF (HA/ZIF/DQ) showed preferable stability under physiological conditions, pH-responsive drug release in an acidic environment and preferential homing capacity to the CD44 receptor-overexpressed HepG2/ADR cells. More importantly, our results revealed that enhanced anticancer efficacy was achieved through the combination of Que and Dox via the tumor microenvironment remodeling effect of Que to potentiate drug penetration into deep tumor tissues.

Sericin grafted multifunctional curcumin loaded fluorinated graphene oxide nanomedicines with charge switching properties for effective cancer cell targeting

Fluorinated graphene has recently gained much attention for cancer drug delivery, owing to its peculiar properties including high electronegativity difference, magnetic resonance imaging contrast agent, and the photothermal effect. However, the hydrophobic nature of fluorinated graphene greatly hinders its application as a biological material. Herein, a novel green method is reported for synthesis of a pH-sensitive charge-reversal and water-soluble fluorinated graphene oxide, modified with polyethyleneimine anchored to sericin-polypeptide (FPS). This nanocarrier was further loaded with curcumin (Cur), and characterized as a nanocarrier for anti-cancer drug delivery. The synthesized nanocarriers contain two different pH-sensitive amide linkages, which are negatively charged in blood pH (≈7.4) and can prolong circulation times. The amide linkages undergo hydrolysis once they reach the mildly acidic condition (pH≈6.5, corresponding to tumor extracellular matrix), and subsequently once reached the lower acidic condition (pH≈5.5, corresponded to endo/lysosomes microenvironment), the FPS charge can be switched to positive (≈+28 mV), which aids the nuclear release. This nanocarrier was designed to selectively enhance cell internalization and nuclear-targeted delivery of curcumin in HeLa, SkBr3 and PC-3 cancer cells. Moreover, FPS-Cur demonstrated high curcumin loading capacity, prolonged curcumin release and promotion of apoptosis in HeLa, SkBr3 and PC-3 cells. Therefore, with its pH-responsive charge-reversal properties, FPS-Cur would be a promising candidate for chemotherapy of cervical, breast and prostate cancers.

Antagonistic Effect of Azoxystrobin Poly (Lactic Acid) Microspheres with Controllable Particle Size on Colletotrichum higginsianum Sacc

Size-controlled azoxystrobin-poly (lactic acid) microspheres (MS) were prepared by an oil/water emulsion solvent evaporation approach. The hydrated mean particle sizes of the MS1, MS2, and MS3 aqueous dispersions were 130.9 nm, 353.4 nm, and 3078.0 nm, respectively. The drug loading and encapsulation efficiency of the azoxystrobin microspheres had a positive relationship with particle size. However, the release rate and percentage of cumulative release were inversely related to particle size. The smaller-sized microspheres had a greater potential to access the target mitochondria. As a result, the more severe oxidative damage of Colletotrichum higginsianum Sacc and higher antagonistic activity were induced by the smaller particle size of azoxystrobin microspheres. The 50% lethal concentrations against Colletotrichum higginsianum Sacc of MS1, MS2, and MS3 were 2.0386 μg/mL, 12.7246 μg/mL, and 21.2905 μg/mL, respectively. These findings reveal that particle size is a critical factor in increasing the bioavailability of insoluble fungicide.

Sericin/RBA embedded gellan gum based smart nanosystem for pH responsive drug delivery

Polysaccharides protein complex offers a green alternative to synthetic polymers in the drug delivery system. Sericin (SC), a natural protein, in combination with rice bran albumin (RBA) and gellan gum (GG) forms a green based protein polysaccharide complex. The sericin functionalized gellan gum-rice bran (SC-GG-RBA) nanocomposites were characterized by different characterization techniques. It shows their prominent ability in balancing the biocompatibility, stability, biodegradability, and functionality of nanocarriers. The nanocomposites exhibited spherical shape with core protein-polysaccharide structures, and the average size was about 218 nm. High amount of Doxorubicin (DOX) was encapsulated into SC-GG-RBA nanocomposites in order to investigate the effective drug release in acidic tumor environment. DOX of 84% was released in vitro condition after 120 h in pH 4.0. DOX loaded green nanocomposites shows IC₅₀ 5 μg/mL which was very low compared to free DOX of 9 μg/mL after treatment with MCF-7 cells. Only 42% of cells were survived after treatment with green nanocomposites. This was due to the effective uptake of nanomaterial by cancer cells and direct release of DOX in cytoplasmic region. Such high performance green nanocomposites have great potential in expanding the utilization of biomaterial from natural resources and development of sensible application in biomedical field.

pH- and redox-responsive nanoparticles composed of charge-reversible pullulan-based shells and disulfide-containing poly(ß-amino ester) cores for co-delivery of a gene and chemotherapeutic agent

A novel pH- and redox-responsive nanoparticle system was designed based on a charge-reversible pullulan derivative (CAPL) and disulfide-containing poly(β-amino ester) (ssPBAE) for the co-delivery of a gene and chemotherapeutic agent targeting hepatoma. The end-alkene groups of ssPBAE were reacted with diethylenetriamine to form amino-modified ssPBAE (NH-ssPBAE). Methotrexate (MTX), a chemotherapy agent, was then conjugated to NH-ssPBAE via an amide bond to obtain the polymeric prodrug ssPBAE-MTX. ssPBAE-MTX exhibited a good capability for condensing genes, including plasmid DNA (pDNA) and tetramethyl rhodamine-labeled DNA (TAMRA-DNA), and almost completely condensed pDNA at the weight ratio of 5/1 to form spherical nanocomplexes with a uniform size. In a D,L-dithiothreitol solution, the ssPBAE-MTX/pDNA nanocomplexes showed rapid release of pDNA and MTX, indicating their redox-responsive capability. CAPL, a pullulan derivative containing β-carboxylic amide bond, was efficiently coated on the surfaces of ssPBAE-MTX/pDNA nanocomplexes to form polysaccharide shells, thus realizing co-loading of the gene and chemotherapeutic agent. CAPL/ssPBAE-MTX/pDNA nanoparticles displayed an obvious pH-responsive charge reversal ability due to the rupture of the β-carboxylic amide bond under the weakly acidic condition. In human hepatoma HepG2 cells, CAPL/ssPBAE-MTX/TAMRA-DNA nanoparticles were efficiently internalized via endocytosis and successfully escaped from the endo/lysosomes into the cytoplasm, and CAPL/ssPBAE-MTX/pDNA nanoparticles remarkably inhibited the cell growth. In summary, this nanoparticle system based on CAPL and ssPBAE showed great potential for combined gene/chemotherapy on hepatomas.

In Situ Monitoring of MicroRNA Replacement Efficacy and Accurate Imaging-Guided Cancer Therapy through Light-Up Inter-Polyelectrolyte Nanocomplexes

Replacement of downregulated tumor-suppressive microRNA (Ts-miRNA) is recognized as an alternative approach for tumor gene therapy. However, in situ monitoring of miRNA replacement efficacy in a real-time manner via noninvasive imaging is continually challenging. Here, glutathione (GSH)-activated light-up peptide-polysaccharide-inter-polyelectrolyte nanocomplexes are established through self-assembly of carboxymethyl dextran with disulfide-bridged ("S-S") oligoarginine peptide (S-Arg4), in which microRNA-34a (miR-34a) and indocyanine green (ICG) are simultaneously embedded and the nanocomplexes are subsequently stabilized by intermolecular cross-linking. Upon confinement within the robust nanocomplexes, the near-infrared fluorescence (NIRF) of ICG is considerably quenched ("off") due to the aggregation-caused quenching effect. However, after intracellular delivery, the disulfide bond in S-Arg4 can be cleaved by intracellular GSH, which leads to the dissociation of nanocomplexes and triggers the simultaneous release of miR-34a and ICG. The NIRF of ICG is concomitantly activated through dequenching of the aggregated ICG. Very interestingly, a good correlation between time-dependent increase in NIRF intensity and miR-34a replacement efficacy is found in nanocomplexes-treated tumor cells and tumor tissues through either intratumoral or intravenous injections. Systemic nanocomplexes-mediated miR-34a replacement significantly suppresses the growth of HepG-2- and MDA-MB-231-derived tumor xenografts, and provides a pronounced survival benefit in these animal models.

Understanding the translocation mechanism of PLGA nanoparticles across round window membrane into the inner ear: a guideline for inner ear drug delivery based on nanomedicine

Background

The round window membrane (RWM) functions as the primary biological barrier for therapeutic agents in the inner ear via local application. Previous studies on inner ear nano-drug delivery systems mostly focused on their pharmacokinetics and distribution in the inner ear, but seldom on the interaction with the RWM. Clarifying the transport mechanism of nanoparticulate carriers across RWM will shed more light on the optimum design of nano-drug delivery systems intended for meeting demands for their clinical application.

Methods

The poly (lactic-co-glycolic acid) nanoparticles (PLGA NPs) encapsulating coumarin-6 were prepared by emulsifying solvent evaporation method. We utilized confocal laser scanning microscope (CLSM) in combination with transmission electron microscope to investigate the transport pathway of PLGA NPs in the RWM. Simultaneously, the concentration and time dependence of NPs across the RWM were also determined. The endocytic mechanism of NPs through this membrane interface was classically analyzed by means of various endocytic inhibitors. The intracellular location of NPs into lysosomes was evaluated using CLSM scanning microscope colocalization analysis. The Golgi-related inhibitors were employed to probe into the function of Golgi and endoplasmic reticulum (ER) in the discharge of NPs out of cells.

Results

PLGA NPs were herein transported through the RWM of a sandwich-like structure into the perilymph via the transcellular pathway. NPs were internalized predominantly via macropinocytosis and caveolin-mediated endocytic pathways. After being internalized, the endocytosed cargos were entrapped within the lysosomal compartments and/or the endoplasmic reticulum/Golgi apparatus which mediated the exocytotic release of NPs.

Conclusion

For the first time, we showed the translocation itinerary of NPs in RWM, providing a guideline for the rational fabrication of inner ear nanoparticulate carriers with better therapeutic effects.

Development of cholate conjugated hybrid polymeric micelles for FXR receptor mediated effective site-specific delivery of paclitaxel

The aim of the present study was to explore the tumor targeting potential of a cholic acid (CA) conjugated polymeric micelle system for the effective delivery of paclitaxel (PTX).

MDR in cancer: Addressing the underlying cellular alterations with the use of nanocarriers

Multidrug resistance (MDR) is associated with a wide range of pathological changes at different cellular and intracellular levels. Nanoparticles (NPs) have been extensively exploited as the carriers of MDR reversing payloads to resistant tumor cells. However, when properly formulated in terms of chemical composition and physicochemical properties, NPs can serve as beyond delivery systems and help overcome MDR even without carrying a load of chemosensitizers or MDR reversing molecular cargos. Whether serving as drug carriers or beyond, a wise design of the nanoparticulate systems to overcome the cellular and intracellular alterations underlying the resistance is imperative. Within the current review, we will initially discuss the cellular changes occurring in resistant cells and how such changes lead to chemotherapy failure and cancer cell survival. We will then focus on different mechanisms through which nanosystems with appropriate chemical composition and physicochemical properties can serve as MDR reversing units at different cellular and intracellular levels according to the changes that underlie the resistance. Finally, we will conclude by discussing logical grounds for a wise and rational design of MDR reversing nanoparticulate systems to improve the cancer therapeutic approaches.

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.

Simply constructed chitosan nanocarriers with precise spatiotemporal control for efficient intracellular drug delivery

A novel intelligent nanocarrier with pH and redox sensitivities was developed based on Carboxymethyl-chitosan (CMCS) and thioglycolic acid conjugated chitosan (TCS) to provide precise spatiotemporal control for efficient intracellular delivery. Doxorubicin (DOX) loaded nanocarriers (DOX/CMCS-TCS NPs) were simply prepared by ionic gelation and then oxidation crosslink. The nanocarriers exhibited decent stability at pH 7.4 for up to 3days and underwent aggregation under acidic pH (5.5) due to protonation of the carboxyl groups on CMCS. The TCS skeleton was stable at pH 5.5 (mimic endo/lysosomes) but disintegrated in the presence of 10mM glutathione (GSH) at pH 7.4 (mimic cytosol). In vitro DOX release from DOX/CMCS-TCS NPs was enhanced at pH 5.5 compared with physiological condition, with 64.2% and 31.6% DOX released in 2h, respectively. While 85.2% of DOX was released within 2h as treated with 10mM GSH, suggesting the release was closely associated with structural disintegration of nanocarriers. The maximum release of DOX was obtained at 10mM GSH and pH 5.5 with 92.3% of DOX released in 5h. Confocal laser scanning microscopy observation indicated that DOX/CMCS-TCS NPs efficiently escaped from endo/lysosomes within 1h incubation with MCF-7 cells and gave the best performance in delivering DOX into nucleus in 2h. Anticancer activity assay revealed that DOX/CMCS-TCS NPs had comparable or even better inhibition of cell viability at high drug concentrations than free DOX, with the IC₅₀ of 0.6μg/mL following 48h incubation. In summary, the simply constructed DOX/CMCS-TCS NPs could not only respond to intracellular delivery temporally, they also achieve rapid release spatially in nucleus, which provide a precise spatiotemporal control of drug delivery for cancer therapy.

Drug-Loaded Polymeric Spherical Nucleic Acids: Enhancing Colloidal Stability and Cellular Uptake of Polymeric Nanoparticles through DNA Surface-Functionalization

Small-sized (∼65 nm) doxorubicin (Dox)-loaded polymeric nanoparticles (PNPs) were modified with oligonucleotides to form colloidally stable Dox-loaded polymeric spherical nucleic acid (Dox-PSNA) nanostructures in biological media. The nucleic acid shell facilitates the cellular uptake of Dox-PSNA, which results in in vitro cytotoxicity against SKOV3 cancer cells.