Targeted intracellular protein delivery based on hyaluronic acid-green tea catechin nanogels

Combination of using prodrug-modified cationic liposome nanocomplexes and a potentiating strategy via targeted co-delivery of gemcitabine and docetaxel for CD44-overexpressed triple negative breast cancer therapy

In this study, novel prodrug-modified cationic liposome nanocomplexes (Combo NCs) were reported for gemcitabine (GEM) and docetaxel (DTX) co-delivery. This nanoplatform exhibited multiple favorable characteristics, such as a 'green' fabrication with a one-step chemical reaction, appropriate size (∼200nm) and distribution (PDI<0.2), low zeta potential (-31.1mv), high drug-loading efficiency (9.3% GEM plus 3.1% DTX, wt%) and pH and enzymatic dual-stimulus-responsive release properties. Immunofluorescence and cellular uptake studies showed that Combo NCs efficiently targeted overexpressed CD44 in MDA-MB-231 carcinoma. In vitro studies revealed that Combo NCs played a critical role in the synergistic induction of cytotoxicity, apoptosis and inhibition of wound healing. Combo NCs were confirmed to exhibit great potency for increasing S phase arrest and remodeling the CDA and dCK balance by decreasing the mRNA expression of CDA down to 0.09-fold and increasing the mRNA expression of dCK by 1.36-fold, remarkably increasing the dCK/CDA ratio to 15.3-fold compared with the blank control. The biodistribution results obtained in vivo revealed an effective accumulation in tumor foci. All of these advantages of Combo NCs contributed to their remarkable anti-tumor efficacy without systemic toxicity as well as their apoptosis-enhancing and anti-proliferative capacities, as determined by TUNEL and Ki67 immunohistochemistry in vivo. Consequently, such a rationally contemplated co-delivery system demonstrated the promising potential of clinical applications for triple-negative breast cancer therapy.

STATE OF SIGNIFICANCE

The Combo NCs were innovatively applied for co-delivery of hydrophilic GEM and hydrophobic DTX. The ester bond linking and shielding effect of HA-GEM made the carriers achieve synchronous release properties, which was determined in in vitro release study. Due to the HA modification, the vectors own great potency for positive targeting to CD44 overexpressed triple-negative breast cancer cells MDA-MB-231. Cytotoxicity and apoptosis studies confirmed the targeting effect and synergism between two drugs. Interestingly, we found in cell cycle study, drug combinations (free combination or Combo NCs) didn't show a rise in G2M phase, which was significantly higher when treated DTX alone. We further discovered the role of DTX in combinations may involve in modulating GEM associated enzymes thus enhancing the efficacy of GEM. Consequently, this nanoplatform provided a novel solution for achieving targeted co-delivery and potentiating effect in cancer therapy.

EGFR and CD44 Dual-Targeted Multifunctional Hyaluronic Acid Nanogels Boost Protein Delivery to Ovarian and Breast Cancers In Vitro and In Vivo

Protein drugs with intracellular targets like Granzyme B (GrB) have demonstrated great proliferative inhibition activity in cancer cells. Their clinical translation, however, relies on the development of safe, efficient, and selective protein-delivery vehicles. Here, we report that epidermal growth factor receptor (EGFR) and CD44 dual-targeted multifunctional hyaluronic acid nanogels (EGFR/CD44-NGs) boost protein delivery to ovarian and breast cancers in vitro and in vivo. EGFR/CD44-NGs obtained via nanoprecipitation and photoclick chemistry from hyaluronic acid derivatives with tetrazole, GE11 peptide/tetrazole, and cystamine methacrylate groups had nearly quantitative loading of therapeutic proteins like cytochrome C (CC) and GrB, a small size of ca. 165 nm, excellent stability in serum, and fast protein release under a reductive condition. Flow cytometry assays showed that EGFR/CD44-NGs exhibited over 6-fold better uptake in CD44 and EGFR-positive SKOV-3 ovarian cancer cells than CD44-NGs. In accordance, GrB-loaded EGFR/CD44-NGs (GrB-EGFR/CD44-NGs) displayed enhanced caspase activity and growth inhibition in SKOV-3 cells as compared to GrB-loaded CD44-NGs (GrB-CD44-NGs) control. Intriguingly, the therapeutic studies in SKOV-3 human ovarian carcinoma and MDA-MB-231 human breast tumor xenografted in nude mice revealed that GrB-EGFR/CD44-NGs at a low dose of 3.85 nmol GrB equiv/kg induced nearly complete growth suppression of both tumors, which was obviously more effective than GrB-CD44-NGs, without causing any adverse effects. EGFR and CD44 dual-targeted multifunctional hyaluronic acid nanogels have appeared as a safe and efficacious platform for cancer protein therapy.

Magnetic Solid-phase Extraction with Fe₃O₄/Molecularly Imprinted Polymers Modified by Deep Eutectic Solvents and Ionic Liquids for the Rapid Purification of Alkaloid Isomers (Theobromine and Theophylline) from Green Tea

Different kinds of deep eutectic solvents (DES) based on choline chloride (ChCl) and ionic liquids (ILs) based on 1-methylimidazole were used to modify Fe3O4/molecularly imprinted polymers (Fe3O4/MIPs), and the resulting materials were applied for the rapid purification of alkaloid isomers (theobromine and theophylline) from green tea with magnetic solid-phase extraction (M-SPE). The M-SPE procedure was optimized using the response surface methodology (RSM) to analyze the maximum conditions. The materials were characterized by Fourier transform infrared spectroscopy (FI-IR) and field emission scanning electron microscopy (FE-SEM). Compared to the ILs-Fe3O4/MIPs, the DESs-Fe3O4/MIPs were developed for the stronger recognition and higher recoveries of the isomers (theophylline and theobromine) from green tea, particularly DES-7-Fe3O4/MIPs. With RSM, the optimal recovery condition for theobromine and theophylline in the M-SPE were observed with ratio of methanol (80%) as the washing solution, methanol/acetic acid (HAc) (8:2) as the eluent at pH 3, and an eluent volume of 4 mL. The practical recoveries of theobromine and theophylline in green tea were 92.27% and 87.51%, respectively, with a corresponding actual extraction amount of 4.87 mg•g-1 and 5.07 mg•g-1. Overall, the proposed approach with the high affinity of Fe3O4/MIPs might offer a novel method for the purification of complex isomer samples.

Polyphenols delivery by polymeric materials: challenges in cancer treatment

Nanotechnology can offer different solutions for enhancing the therapeutic efficiency of polyphenols, a class of natural products widely explored for a potential applicability for the treatment of different diseases including cancer. While possessing interesting anticancer properties, polyphenols suffer from low stability and unfavorable pharmacokinetics, and thus suitable carriers are required when planning a therapeutic protocol. In the present review, an overview of the different strategies based on polymeric materials is presented, with the aim to highlight the strengths and the weaknesses of each approach and offer a platform of ideas for researchers working in the field.

Targeted glioma chemotherapy by cyclic RGD peptide-functionalized reversibly core-crosslinked multifunctional poly(ethylene glycol)-b-poly(ε-caprolactone) micelles

Cyclic RGD peptide-functionalized reversibly core-crosslinked biodegradable poly(ethylene glycol)-b-poly(ε-caprolactone) (PEG-PCL) micelles (cRGD-RCCMs) were designed and developed for highly potent and targeted glioma chemotherapy. To achieve crosslinkable core, dithiolane-functionalized trimethylene carbonate (DTC) was incorporated into PCL block. Interestingly, cRGD-RCCMs displayed a high doxorubicin (DOX) loading content of ∼18wt%, small hydrodynamic size of ∼50nm, and excellent colloidal stability with minimum drug leakage under physiological conditions while fast DOX release under cytoplasmic-mimicking reductive environments. MTT, confocal microscopy and flow cytometry measurement results pointed out that cRGD-RCCMs with 30% cRGD surface density (cRGD30-RCCMs) showed an evident selectivity, efficient cytoplasmic drug release, and superior antitumor activity to clinically used pegylated liposomal doxorubicin (DOX-LPs) in α_vβ₃ integrin overexpressing U87MG glioblastoma cells. Strikingly, DOX-loaded cRGD30-RCCMs demonstrated a prolonged circulation time showing an elimination half-life of ∼4.7h, three times exceeding that of the non-crosslinked counterparts, and a remarkably enhanced tumor accumulation of 7.7%ID/g. Furthermore, in vivo therapeutic studies revealed that DOX-loaded cRGD30-RCCMs effectively suppressed tumor growth, significantly prolonged survival time, and lessened side effects in subcutaneous U87MG glioblastoma-bearing nude mice. These reversibly core-crosslinked multifunctional biodegradable micelles might be developed into advanced and clinically viable targeted anticancer nanomedicines.

STATEMENT OF SIGNIFICANCE

Nanomedicines based on biodegradable micelles and nanoparticles offer a most promising treatment for malignant tumors. The therapeutic outcomes of current nanomedicines are, however, trimmed by their instability, low tumor retention, inefficient tumor cell uptake, and inferior drug release control. We report herein that cRGD-functionalized, rapidly glutathione-responsive, and reversibly core-crosslinked biodegradable micellar doxorubicin based on PEG-PCL block copolymer mediates potent and targeted glioma chemotherapy, affording significantly better treatment efficacy and lower systemic toxicity than the non-crosslinked micellar doxorubicin and clinically used pegylated liposomal doxorubicin controls. These reversibly core-crosslinked multifunctional biodegradable micelles have emerged as a robust, simple, versatile, and safe nanoplatform that might elegantly bridge the gap between the scientific and translational anticancer nanomedicine research.

Hyaluronic Acid/PLGA Core/Shell Fiber Matrices Loaded with EGCG Beneficial to Diabetic Wound Healing

During the last few decades, considerable research on diabetic wound healing strategies has been performed, but complete diabetic wound healing remains an unsolved problem, which constitutes an enormous biomedical burden. Herein, hyaluronic acid (HA)/poly(lactic-co-glycolic acid, PLGA) core/shell fiber matrices loaded with epigallocatechin-3-O-gallate (EGCG) (HA/PLGA-E) are fabricated by coaxial electrospinning. HA/PLGA-E core/shell fiber matrices are composed of randomly-oriented sub-micrometer fibers and have a 3D porous network structure. EGCG is uniformly dispersed in the shell and sustainedly released from the matrices in a stepwise manner by controlled diffusion and PLGA degradation over four weeks. EGCG does not adversely affect the thermomechanical properties of HA/PLGA-E matrices. The number of human dermal fibroblasts attached on HA/PLGA-E matrices is appreciably higher than that on HA/PLGA counterparts, while their proliferation is steadily retained on HA/PLGA-E matrices. The wound healing activity of HA/PLGA-E matrices is evaluated in streptozotocin-induced diabetic rats. After two weeks of surgical treatment, the wound areas are significantly reduced by the coverage with HA/PLGA-E matrices resulting from enhanced re-epithelialization/neovascularization and increased collagen deposition, compared with no treatment or HA/PLGA. In conclusion, the HA/PLGA-E matrices can be potentially exploited to craft strategies for the acceleration of diabetic wound healing and skin regeneration.

Redox-Sensitive and Intrinsically Fluorescent Photoclick Hyaluronic Acid Nanogels for Traceable and Targeted Delivery of Cytochrome c to Breast Tumor in Mice

In spite of their high specificity and potency, few protein therapeutics are applied in clinical cancer therapy owing to a lack of safe and efficacious delivery systems. Here, we report that redox-sensitive and intrinsically fluorescent photoclick hyaluronic acid nanogels (HA-NGs) show highly efficient loading and breast tumor-targeted delivery of cytochrome c (CC). HA-NGs were obtained from hyaluronic acid-graft-oligo(ethylene glycol)-tetrazole (HA-OEG-Tet) via inverse nanoprecipitation and catalyst-free photoclick cross-linking with l-cystine dimethacrylamide (MA-Cys-MA). HA-NGs exhibited a superb CC loading content of up to 40.6 wt %, intrinsic fluorescence (λem = 510 nm), and a small size of ca. 170 nm. Notably, CC-loaded nanogels (CC-NGs) showed a fast glutathione-responsive protein release behavior. Importantly, released CC maintained its bioactivity. MTT assays revealed that CC-NGs were highly potent with a low IC50 of 3.07 μM to CD44+ MCF-7 human breast tumor cells. Confocal microscopy observed efficient and selective internalization of fluorescent HA-NGs into MCF-7 cells. Interestingly, HA-NGs exhibited also effective breast tumor penetration. The therapeutic results demonstrated that CC-NGs effectively inhibited the growth of MCF-7 breast tumor xenografts at a particularly low dose of 80 or 160 nmol CC equiv./kg. Moreover, CC-NGs did not cause any change in mice body weight, corroborating their low systemic side effects. Redox-sensitive and intrinsically fluorescent photoclick hyaluronic acid nanogels have appeared as a "smart" protein delivery nanoplatform enabling safe, efficacious, traceable, and targeted cancer protein therapy in vivo.