Hyaluronic acid targeting of CD44 for cancer therapy: from receptor biology to nanomedicine

Prussian blue nanoparticles: Synthesis, surface modification, and application in cancer treatment

This review outlines recently developed Prussian blue nanoparticle (PB NPs)-based multimodal imaging-guided chemo-photothermal strategies for cancer diagnosis and treatment in order to provide insight into the future of the field. The primary limitation of existing therapeutics is the lack of selectivity in drug delivery: they target healthy and cancerous cells alike. In this paper, we provide a thorough review of diverse synthetic and surface engineering techniques for PB NP fabrication. We have elucidated the various targeting approaches employed to deliver the therapeutic and imaging ligands into the tumor area, and outlined methods for enhancement of the tumor ablative ability of the NPS, including several important combinatorial approaches. In addition, we have summarized different in vitro and in vivo effects of PB NP-based therapies used to overcome both systemic and tumor-associated local barriers. An important new approach - PB NP-based immune drug delivery, which is an exciting and promising strategy to overcome cancer resistance and tumor recurrence - has been discussed. Finally, we have discussed the current understanding of the toxicological effects of PB NPs and PB NP-based therapeutics. We conclude that PB NP-based multimodal imaging-guided chemo-photothermal therapy offers new treatment strategies to overcome current hurdles in cancer diagnosis and treatment.

Hyaluronic acid formulation of near infrared fluorophores optimizes surgical imaging in a prostate tumor xenograft

The presence of positive surgical margins confers an increased risk of biochemical relapse and need for salvage therapy in men undergoing radical prostatectomy. Image-guided surgery using near-infrared (NIR) fluorescent contrast agents is a potential method to detect remaining cancerous tissue. The objective of this study was to evaluate three hyaluronic acid (HA) nanoparticle (NP) formulations loaded with NIR fluorophore for their ability to contrast-enhance prostate cancer. HA was modified by conjugation with the hydrophobic ligand, aminopropyl-1-pyrenebutanamide to drive nanoparticle self-assembly. Indocyanine green (ICG) was physicochemically entrapped in the HA-NP, termed NanoICG. Alternatively, Cy7.5 was directly conjugated to amphiphilic HA, termed NanoCy7.5. NanoCy7.5 was synthesized with two HA molecular weights to determine the HA size contribution to delivery to PC3 prostate tumor xenografts. Contrast-enhancement of the tumors and relative biodistribution were assessed by a series of fluorescence imaging, image-guided surgery with spectroscopy, and microscopic techniques. Intravenously administered NanoICG improved tumor signal-to-noise ratio (SNR) at 24 h over ICG by 2.9-fold. NanoCy7.5 with 10 kDa and 100 kDa HA improved tumor SNR by 6.6- and 3.1-fold over Cy7.5 alone, respectively. The PC3 xenograft was clearly identified with the image-guided system providing increased contrast enhancement compared to surrounding tissue for NanoICG and NanoCy7.5 with 10 kDa HA. NIR fluorescence microscopy showed that Cy7.5 in NPs with 10 kDa HA were distributed throughout the tumor, while NanoCy7.5 with 100 kDa HA or NanoICG delivered dye mainly to the edge of the tumor. CD31 staining suggested that PC3 tumors are poorly vascularized. These studies demonstrate the efficacy of a panel of HA-derived NPs in identifying prostate tumors in vivo, and suggest that by tuning the structural properties of these NPs, optimized delivery can be achieved to poorly vascularized tumors.

STATEMENT OF SIGNIFICANCE

We have demonstrated the potential of a panel of near-infrared fluorescent (NIRF) nanoparticles (NPs) for image-guided surgery in a prostate cancer xenograft model. Image-guided surgery and imaging of organs ex vivo showed greater tumor signal and contrast when mice were administered NIRF dyes that were covalently conjugated to (NanoCy7.5_10k-PBA) or physicochemically entrapped in (NanoICG_PBA) hyaluronic acid (HA) NPs, compared to free dyes. These results show the potential to use these NPs as tools to detect the margins of tumors and to differentiate healthy and tumor tissue intraoperatively. Moreover, this project provides insight into selecting optimal formulation strategies for poorly vascularized tumors.

Bacterial components as naturally inspired nano-carriers for drug/gene delivery and immunization: Set the bugs to work?

Drug delivery is a rapidly growing area of research motivated by the nanotechnology revolution, the ideal of personalized medicine, and the desire to reduce the side effects of toxic anti-cancer drugs. Amongst a bewildering array of different nanostructures and nanocarriers, those examples that are fundamentally bio-inspired and derived from natural sources are particularly preferred. Delivery of vaccines is also an active area of research in this field. Bacterial cells and their components that have been used for drug delivery, include the crystalline cell-surface layer known as "S-layer", bacterial ghosts, bacterial outer membrane vesicles, and bacterial products or derivatives (e.g. spores, polymers, and magnetic nanoparticles). Considering the origin of these components from potentially pathogenic microorganisms, it is not surprising that they have been applied for vaccines and immunization. The present review critically summarizes their applications focusing on their advantages for delivery of drugs, genes, and vaccines.

Hyaluronic Acid in the Third Millennium

Since its first isolation in 1934, hyaluronic acid (HA) has been studied across a variety of research areas. This unbranched glycosaminoglycan consisting of repeating disaccharide units of N-acetyl-d-glucosamine and d-glucuronic acid is almost ubiquitous in humans and in other vertebrates. HA is involved in many key processes, including cell signaling, wound reparation, tissue regeneration, morphogenesis, matrix organization and pathobiology, and has unique physico-chemical properties, such as biocompatibility, biodegradability, mucoadhesivity, hygroscopicity and viscoelasticity. For these reasons, exogenous HA has been investigated as a drug delivery system and treatment in cancer, ophthalmology, arthrology, pneumology, rhinology, urology, aesthetic medicine and cosmetics. To improve and customize its properties and applications, HA can be subjected to chemical modifications: conjugation and crosslinking. The present review gives an overview regarding HA, describing its history, physico-chemical, structural and hydrodynamic properties and biology (occurrence, biosynthesis (by hyaluronan synthases), degradation (by hyaluronidases and oxidative stress), roles, mechanisms of action and receptors). Furthermore, both conventional and recently emerging methods developed for the industrial production of HA and its chemical derivatization are presented. Finally, the medical, pharmaceutical and cosmetic applications of HA and its derivatives are reviewed, reporting examples of HA-based products that currently are on the market or are undergoing further investigations.

Cancer Stem Cell Metabolism and Potential Therapeutic Targets

Malignant tumors contain heterogeneous populations of cells in various states of proliferation and differentiation. The presence of cancer stem or initiating cells is a well-established concept wherein quiescent and poorly differentiated cells within a tumor mass contribute to drug resistance, and under permissive conditions, are responsible for tumor recurrence and metastasis. A number of studies have identified molecular markers that are characteristic of tissue-specific cancer stem cells (CSCs). Isolation of CSCs has enabled studies on the metabolic status of CSCs. As metabolic plasticity is a hallmark of cancer cell adaptation, the intricacies of CSC metabolism and their phenotypic behavior are critical areas of research. Unlike normal stem cells, which rely heavily on oxidative phosphorylation (OXPHOS) as their primary source of energy, or cancer cells, which are primarily glycolytic, CSCs demonstrate a unique metabolic flexibility. CSCs can switch between OXPHOS and glycolysis in the presence of oxygen to maintain homeostasis and, thereby, promote tumor growth. Here, we review key factors that impact CSC metabolic phenotype including heterogeneity of CSCs across different histologic tumor types, tissue-specific variations, tumor microenvironment, and CSC niche. Furthermore, we discuss how targeting key players of glycolytic and mitochondrial pathways has shown promising results in cancer eradication and attenuation of disease recurrence in preclinical models. In addition, we highlight studies on other potential therapeutic targets including complex interactions within the microenvironment and cellular communications in the CSC niche to interfere with CSC growth, resistance, and metastasis.

CD44 targeted PLGA nanomedicines for cancer chemotherapy

In recent years scientific community has drawn a great deal of attention towards understanding the enigma of cluster of differentiation-44 (CD44) in order to deliver therapeutic agents more selectively towards tumor tissues. Moreover, its over-expression in variety of solid tumors has attracted drug delivery researchers to target this receptor with nanomedicines. Conventional nanomedicines based on biodegradable polymers such as poly(lactide-co-glycolide) (PLGA) are often associated with insufficient cellular uptake by cancer cells, due to lack of active targeting moiety on their surface. Therefore, to address this limitation, CD44 targeted PLGA nanomedicines has gained considerable interest for enhancing the efficacy of chemotherapeutic agents. In this review, we have elaborately discussed the recent progress in the design and synthesis of CD44 targeted PLGA nanomedicines used to improve tumor-targeted drug delivery. We have also discussed strategies based on co-targeting of CD44 with other targeting moieties such as folic acid, human epidermal growth factor 2 (HER2), monoclonal antibodies using PLGA based nanomedicines.

Hyaluronic acid conjugated nanoparticle delivery of siRNA against TWIST reduces tumor burden and enhances sensitivity to cisplatin in ovarian cancer

TWIST protein is critical to development and is activated in many cancers. TWIST regulates epithelial-mesenchymal transition, and is linked to angiogenesis, metastasis, cancer stem cell phenotype, and drug resistance. The majority of epithelial ovarian cancer (EOC) patients with metastatic disease respond well to first-line chemotherapy but most relapse with disease that is both metastatic and drug resistant, leading to a five-year survival rate under 20%. We are investigating the role of TWIST in mediating these relapses. We demonstrate TWIST-siRNA (siTWIST) and a novel nanoparticle delivery platform to reverse chemoresistance in an EOC model. Hyaluronic-acid conjugated mesoporous silica nanoparticles (MSN-HAs) carried siTWIST into target cells and led to sustained TWIST knockdown in vitro. Mice treated with siTWIST-MSN-HA and cisplatin exhibited specific tumor targeting and reduction of tumor burden. This platform has potential application for overcoming clinical challenges of tumor cell targeting, metastasis and chemoresistance in ovarian and other TWIST overexpressing cancers.

Inorganic kernel - Supported asymmetric hybrid vesicles for targeting delivery of STAT3-decoy oligonucleotides to overcome anti-HER2 therapeutic resistance of BT474R

As a recombinant humanized monoclonal antibody that targets the extracellular region of HER2 tyrosine kinase receptor, trastuzumab (TRAZ) has demonstrated comparable clinical efficacy and improved survival in patients with HER2-positive breast cancer. Nevertheless, the therapeutic potential of TRAZ is often limited due to its frequent resistance to anti-HER2 therapy. Therefore, we investigate the reversal effect of STAT3-specific decoy oligonucleotides (STAT3-decoy ODNs) on TRAZ resistance, which contain the consensus sequence within the targeted gene promoter of STAT3. Considering the shortcomings of poor cellular permeability and rapid degradation in vivo limit the further clinical applications of ODNs, we report here an asymmetric hybrid lipid/polymer vesicles with calcium phosphate as the solid kernel (CaP@HA). Through hyaluronan-mediated CD44 targeting, the constructed vesicles can specifically carry STAT3-decoy ODNs into TRAZ-resistant breast cancer cells and then regulate TRAZ-induced apoptosis. In comparison with the native ones, ODNs packaged with CaP@HA showed significantly increased serum stability, cellular transfection, synergistic cytotoxicity and apoptosis in vitro. The improved TRAZ sensitization is attributed to the blockade of STAT3 signaling as well as the expression of downstream target genes associated with TRAZ resistance. With the synergistic action of STAT3-decoy ODNs loaded CaP@HA, TRAZ inhibited the growth of its resistant breast cancer xenograft dramatically and induced significant tumor cell apoptosis in vivo. These results suggested that CaP@HA mediated targeted delivery of STAT3-decoy ODNs might be a promising new strategy to overcome anti-HER2 resistance in breast cancer therapy.

Polysaccharide-Based Controlled Release Systems for Therapeutics Delivery and Tissue Engineering: From Bench to Bedside

Polysaccharides or polymeric carbohydrate molecules are long chains of monosaccharides that are linked by glycosidic bonds. The naturally based structural materials are widely applied in biomedical applications. This article covers four different types of polysaccharides (i.e., alginate, chitosan, hyaluronic acid, and dextran) and emphasizes their chemical modification, preparation approaches, preclinical studies, and clinical translations. Different cargo fabrication techniques are also presented in the third section. Recent progresses in preclinical applications are then discussed, including tissue engineering and treatment of diseases in both therapeutic and monitoring aspects. Finally, clinical translational studies with ongoing clinical trials are summarized and reviewed. The promise of new development in nanotechnology and polysaccharide chemistry helps clinical translation of polysaccharide-based drug delivery systems.

Calcium phosphate-based nanosystems for advanced targeted nanomedicine

Synthetic calcium phosphates (CaPs) are the most widely accepted bioceramics for the repair and reconstruction of bone tissue defects. The recent advancements in materials science have prompted a rapid progress in the preparation of CaPs with nanometric dimensions, tailored surface characteristics, and colloidal stability opening new perspectives in their use for applications not strictly related to bone. In particular, the employment of CaPs nanoparticles as carriers of therapeutic and imaging agents has recently raised great interest in nanomedicine. CaPs nanoparticles, as well as other kinds of nanoparticles, can be engineered to specifically target the site of the disease (cells or organs), thus minimizing their dispersion in the body and undesired organism-nanoparticles interactions. The most promising and efficient approach to improve their specificity is the 'active targeting', where nanoparticles are conjugated with a targeting moiety able to recognize and bind with high efficacy and selectivity to receptors that are highly expressed only in the therapeutic site. The aim of this review is to give an overview on advanced targeted nanomedicine with a focus on the most recent reports on CaP nanoparticles-based systems, specifically designed for the active targeting. The distinctive characteristics of CaP nanoparticles with respect to the other kinds of nanomaterials used in nanomedicine are also discussed.

Transduction Methods for Cytosolic Delivery of Proteins and Bioconjugates into Living Cells

The human organism and its constituting cells rely on interplay between multiple proteins exerting specific functions. Progress in molecular biotechnologies has facilitated the production of recombinant proteins. When administrated to patients, recombinant proteins can provide important healthcare benefits. To date, most therapeutic proteins must act from the extracellular environment, with their targets being secreted modulators or extracellular receptors. This is because proteins cannot passively diffuse across the plasma membrane into the cytosol. To expand the scope of action of proteins for cytosolic targets (representing more than 40% of the genome) effective methods assisting protein cytosolic entry are being developed. To date, direct protein delivery is extremely tedious and inefficient in cultured cells, even more so in animal models of pathology. Novel techniques are changing this limitation, as recently developed in vitro methods can robustly convey large amount of proteins into cell cultures. Moreover, advances in protein formulation or protein conjugates are slowly, but surely demonstrating efficiency for targeted cytosolic entry of functional protein in vivo in tumor xenograft models. In this review, various methods and recently developed techniques for protein transport into cells are summarized. They are put into perspective to address the challenges encountered during delivery.

Nanoplatform Assembled from a CD44-Targeted Prodrug and Smart Liposomes for Dual Targeting of Tumor Microenvironment and Cancer Cells

The tumor microenvironment (TME) plays a critical role in tumor initiation, progression, invasion, and metastasis. Therefore, a therapy that combines chemotherapeutic drugs with a TME modulator could be a promising route for cancer treatment. This paper reports a nanoplatform self-assembled from a hyaluronic acid (HA)-paclitaxel (PTX) (HA-PTX) prodrug and marimastat (MATT)-loaded thermosensitive liposomes (LTSLs) (MATT-LTSLs) for the dual targeting of the TME and cancer cells. Interestingly, the prodrug HA-PTX can self-assemble on both positively and negatively charged liposomes, forming hybrid nanoparticles (HNPs, 100 nm). Triggered by mild hyperthermia, HA-PTX/MATT-LTSLs HNPs rapidly release their payloads into the extracellular environment, and the released HA-PTX quickly enters 4T1 cells through a CD44-HA affinity. The HNPs possess promoted tumor accumulation (1.6-fold), exhibit deep tumor penetration, and significantly inhibit the tumor growth (10-fold), metastasis (100%), and angiogenesis (10-fold). Importantly, by targeting the TME and maintaining its integrity via inhibiting the expression and activity of matrix metalloproteinases (>5-fold), blocking the fibroblast activation by downregulating the TGF-β1 expression (5-fold) and suppressing the degradation of extracellular matrix, the HNPs allow for significant metastasis inhibition. Overall, these findings indicate that a prodrug of an HA-hydrophobic-active compound and liposomes can be self-assembled into a smart nanoplatform for the dual targeting of the TME and tumor cells and efficient combined treatment; additionally, the co-delivery of MATT and HA-PTX with the HNPs is a promising approach for the treatment of metastatic cancer. This study creates opportunities for fabricating multifunctional nanodevices and offers an efficient strategy for disease therapy.

Cell-penetrating Peptide-modified Targeted Drug-loaded Phase-transformation Lipid Nanoparticles Combined with Low-intensity Focused Ultrasound for Precision Theranostics against Hepatocellular Carcinoma

Objective: Prepare a multifunctional ultrasound molecular probe, hyaluronic acid-mediated cell-penetrating peptide-modified 10-hydroxycamptothecin-loaded phase-transformation lipid nanoparticles (HA/CPPs-10-HCPT-NPs), and to combine HA/CPPs-10-HCPT-NPs with low-intensity focused ultrasound (LIFU) for precision theranostics against hepatocellular carcinoma (HCC).

Methods: HA/CPPs-10-HCPT-NPs were prepared using thin-film dispersion, ultrasound emulsification, and electrostatic effects. HA/CPPs-10-HCPT-NPs were characterized for particle size, zeta potential, encapsulation efficiency and drug-loading efficiency. In vitro, HA/CPPs-10-HCPT-NPs were tested for acoustic droplet vaporization (ADV) at different time points/acoustic intensities; the ability of HA/CPPs-10-HCPT-NPs to target SMMC-7721 cells was detected by confocal laser scanning microscopy (CLSM); the penetrating ability of CG-TAT-GC-modified NPs was verified by CLSM in a 3D multicellular tumor spheroid (MCTS) model; the effect of HA/CPPs-10-HCPT-NPs combined with LIFU on killing SMMC-7721 cells was measured by CCK-8 and flow cytometry. In vivo, the tumor-target efficiency of HA/CPPs-10-HCPT-NPs was evaluated by a small-animal fluorescence imaging system and CLSM; the enhanced ultrasound imaging efficiency of HA/CPPs-10-HCPT-NPs combined with LIFU was measured by an ultrasound imaging analyzer; the therapeutic effect of HA/CPPs-10-HCPT-NPs combined with LIFU was evaluated by tumor volume, tumor inhibition rate, and staining (hematoxylin and eosin (H & E), proliferating cell nuclear antigen (PCNA) and TUNEL).

Results: Mean particle size and mean zeta potential of HA/CPPs-10-HCPT-NPs were 284.2±13.3 nm and - 16.55±1.50 mV, respectively. HA/CPPs-10-HCPT-NPs could bind to SMMC-7721 cells more readily than CPPs-10-HCPT-NPs. Penetration depth into 3D MCTS of HA/CPPs-10-HCPT-NPs was 2.76-fold larger than that of NPs without CG-TAT-GC. HA/CPPs-10-HCPT-NPs could enhance ultrasound imaging by undergoing ADV triggered by LIFU. HA/CPPs-10-HCPT-NPs+LIFU group demonstrated significantly higher efficiency of anti-proliferation and apoptosis percentage than all other groups. In mouse liver tumor xenografts, HA/CPPs-10-HCPT-NPs could target tumor sites and enhance ultrasound imaging under LIFU. HA/CPPs-10-HCPT-NPs+LIFU group had a significantly smaller tumor volume, lower proliferative index (PI), and higher tumor inhibition and apoptotic index (AI) than all other groups.

Conclusions: Combined application of HA/CPPs-10-HCPT-NPs and LIFU should be a valuable and promising strategy for precise HCC theranostics.

Mesoporous silica nanoparticles functionalized with hyaluronic acid. Effect of the biopolymer chain length on cell internalization

Mesoporous silica nanoparticles (MSNs) were functionalized with amino groups (MSN-NH₂) and then with hyaluronic acid, a biocompatible biopolymer which can be recognized by CD44 receptors in tumor cells, to obtain a targeting drug delivery system. To this purpose, three hyaluronic acid samples differing for the molecular weight, namely HA_S (8-15 kDa), HA_M (30-50 kDa) and HA_L (90-130 kDa), were used. The MSN-HA_S, MSN-HA_M, and MSN-HA_L materials were characterized through zeta potential and dynamic light scattering measurements at pH = 7.4 and T = 37 °C to simulate physiological conditions. While zeta potential showed an increasing negative value with the increase of the HA chain length, an anomalous value of the hydrodynamic diameter was observed for MSN-HA_L, which was smaller than that of MSN-HA_S and MSN-HA_M samples. The cellular uptake of MSN-HA samples on HeLa cells at 37 °C was studied by optical and electron microscopy. HA chain length affected significantly the cellular uptake that occurred at a higher extent for MSN-NH₂ and MSN-HA_S than for MSN-HA_M and MSN-HA_L samples. Cellular uptake experiments carried out at 4 °C showed that the internalization process was inhibited for MSN-HA samples but not for MSN-NH₂. This suggests the occurrence of two different mechanisms of internalization. For MSN-NH₂ the uptake is mainly driven by the attractive electrostatic interaction with membrane phospholipids, while MSN-HA internalization involves CD44 receptors overexpressed in HeLa cells.

Design of peptide mimetics to block pro-inflammatory functions of HA fragments

Hyaluronan is a simple extracellular matrix polysaccharide that actively regulates inflammation in tissue repair and disease processes. The native HA polymer, which is large (>500 kDa), contributes to the maintenance of homeostasis. In remodeling and diseased tissues, polymer size is strikingly polydisperse, ranging from <10 kDa to >500 kDa. In a diseased or stressed tissue context, both smaller HA fragments and high molecular weight HA polymers can acquire pro-inflammatory functions, which result in the activation of multiple receptors, triggering pro-inflammatory signaling to diverse stimuli. Peptide mimics that bind and scavenge HA fragments have been developed, which show efficacy in animal models of inflammation. These studies indicate both that HA fragments are key to driving inflammation and that scavenging these is a viable therapeutic approach to blunting inflammation in disease processes. This mini-review summarizes the peptide-based methods that have been reported to date for blocking HA signaling events as an anti-inflammatory therapeutic approach.

Combinational siRNA delivery using hyaluronic acid modified amphiphilic polyplexes against cell cycle and phosphatase proteins to inhibit growth and migration of triple-negative breast cancer cells

Triple-negative breast cancer is an aggressive form of breast cancer with few therapeutic options if it recurs after adjuvant chemotherapy. RNA interference could be an alternative therapy for metastatic breast cancer, where small interfering RNA (siRNA) can silence the expression of aberrant genes critical for growth and migration of malignant cells. Here, we formulated a siRNA delivery system using lipid-substituted polyethylenimine (PEI) and hyaluronic acid (HA), and characterized the size, ζ-potential and cellular uptake of the nanoparticulate delivery system. Higher cellular uptake of siRNA by the tailored PEI/HA formulation suggested better interaction of complexes with breast cancer cells due to improved physicochemical characteristics of carrier and HA-binding CD44 receptors. The siRNAs against specific phosphatases that inhibited migration of MDA-MB-231 cells were then identified using library screen against 267 protein-tyrosine phosphatases, and siRNAs to inhibit cell migration were further validated. We then assessed the combinational delivery of a siRNA against CDC20 to decrease cell growth and a siRNA against several phosphatases shown to decrease migration of breast cancer cells. Combinational siRNA therapy against CDC20 and identified phosphatases PPP1R7, PTPN1, PTPN22, LHPP, PPP1R12A and DUPD1 successfully inhibited cell growth and migration, respectively, without interfering the functional effect of the co-delivered siRNA. The identified phosphatases could serve as potential targets to inhibit migration of highly aggressive metastatic breast cancer cells. Combinational siRNA delivery against cell cycle and phosphatases could be a promising strategy to inhibit both growth and migration of metastatic breast cancer cells, and potentially other types of metastatic cancer.

STATEMENT OF SIGNIFICANCE

The manuscript investigated the efficacy of a tailored polymeric siRNA delivery system formulation as well as combinational siRNA therapy in metastatic breast cancer cells to inhibit malignant cell growth and migration. The siRNA delivery was undertaken by non-viral means with PEI/HA. We identified six phosphatases that could be critical targets to inhibit migration of highly aggressive metastatic breast cancer cells. We further report on specifically targeting cell cycle and phosphatase proteins to decrease both malignant cell growth and migration simultaneously. Clinical gene therapy against metastatic breast cancer with effective and safe delivery systems is urgently needed to realize the potential of molecular medicine in this deadly disease and our studies in this manuscript is intended to facilitate this endeavor.

Dual pH-responsive multifunctional nanoparticles for targeted treatment of breast cancer by combining immunotherapy and chemotherapy

In the present study, a dual pH-responsive multifunctional nanoparticle system was designed for combining immunotherapy and chemotherapy to treat breast cancer through targeting immune cells and cancer cells. A proven anti-tumor immune regulator, R848, was encapsulated with poly(L-histidine) (PHIS) to form PHIS/R848 nanocores. Doxorubicin (DOX) was conjugated to hyaluronic acid (HA) through an acid-cleavable hydrazone bond linkage to synthesize polymeric prodrug HA-DOX, which was subsequently coated outside PHIS/R848 nanocores to form HA-DOX/PHIS/R848 nanoparticles. Ionization of PHIS around pH 6.5 (a pH value close to that of tumor microenvironment) switched the nature of this material from hydrophobic to hydrophilic, and thus triggered the release of R848 to exert immunoregulatory action. The rupture of hydrazone bond in HA-DOX at about pH 5.5 (pH of endo/lysosomes) accelerated the release of DOX to exert cytotoxic effects. In immune cells, PHIS/R848 nanocores exhibited strong immunoregulatory activities similar to those induced by free R848. In breast cancer cells overexpressing CD44, HA-DOX was specially internalized by CD44-mediated endocytosis and significantly inhibited the cell growth. In 4T1 tumor-bearing mice, HA-DOX/PHIS/R848 nanoparticles showed excellent tumor-targeting ability and remarkably inhibited the tumor growth by regulating tumor immunity and killing tumor cells. In summary, this multifunctional nanoparticle system could deliver R848 and DOX respectively to tumor microenvironment and breast cancer cells to achieve synergistic effects of immunotherapy and chemotherapy against breast cancer.

STATEMENT OF SIGNIFICANCE

Combination of immunotherapy and chemotherapy is becoming a promising new treatment for cancer. The major challenge is to target cancer and immune cells simultaneously and specifically. In this study, a dual pH-responsive multifunctional nanoparticle system based on poly(L-histidine) and hyaluronic acid was designed for co-loading R848 (immune-regulator) and doxorubicin (chemotherapeutic drug) through different encapsulation modes. By responding to the acidic pHs of tumor microenvironment and intracellular organelles, this multifunctional nanoparticle system could release R848 extracellularly and deliver DOX targetedly to breast cancer cells, thus achieving synergistic effects of immunotherapy and chemotherapy against breast cancer.

High and low molecular weight hyaluronic acid-coated gold nanobipyramids for photothermal therapy

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer. It is known that hyaluronic acid (HA) binds CD44 receptors, which are overexpressed on the surface of TNBC cells. To optimize the targeting ability of HA, in this study we coated gold nanobipyramids (GBPs) with high and low molecular weight HA (380 kDa and 102 kDa), named GBPs@h-HA and GBPs@l-HA, respectively. GBPs@l-HA and GBPs@h-HA had excellent stability when dispersed in water and PBS (pH 7.4) for seven days. The HA density was calculated by the ratio of HA to GBPs@l-HA and GBPs@h-HA, which was 13.22 and 4.77, respectively. The two nanoparticles displayed good photostability, which was evaluated by their photothermal performance and similar biocompatibility. Inductively coupled plasma atomic emission spectrometry (ICP-AES) revealed superior cellular uptake of GBPs@h-HA over GBPs@l-HA. Upon 808 nm laser irradiation, the GBPs@h-HA also showed higher therapeutic efficacy than GBPs@l-HA both in vitro and in vivo. Overall, our study demonstrates that the molecular weight of HA plays an important role in the targeting ability and thus photothermal therapeutic efficacy of HA-coated gold nanobipyramids.

Triple-negative breast cancer (TNBC) is an aggressive subtype of breast cancer. Hyaluronic acid (HA) could bind CD44 receptors, which are overexpressed on the surface of TNBC cells. Upon 808 nm laser irradiation, the GBPs@HA showed high therapeutic efficacy in vivo.

Hyaluronic Acid-Based pH-Sensitive Polymer-Modified Liposomes for Cell-Specific Intracellular Drug Delivery Systems

For the enhancement of therapeutic effects and reduction of side effects derived from anticancer drugs in cancer chemotherapy, it is imperative to develop drug delivery systems with cancer-specificity and controlled release function inside cancer cells. pH-sensitive liposomes are useful as an intracellular drug delivery system because of their abilities to transfer their contents into the cell interior through fusion or destabilization of endosome, which has weakly acidic environment. We earlier reported liposomes modified with various types of pH-sensitive polymers based on synthetic polymers and biopolymers as vehicles for intracellular drug delivery systems. In this study, hyaluronic acid (HA)-based pH-sensitive polymers were designed as multifunctional polymers having not only pH-sensitivity but also targeting properties to cells expressing CD44, which is known as a cancer cell surface marker. Carboxyl group-introduced HA derivatives of two types, MGlu-HA and CHex-HA, which have a more hydrophobic side chain structure than that of MGlu-HA, were synthesized by reaction with various dicarboxylic anhydrides. These polymer-modified liposomes were stable at neutral pH, but showed content release under weakly acidic conditions. CHex-HA-modified liposomes delivered their contents into CD44-expressing cells more efficiently than HA-modified or MGlu-HA-modified liposomes or unmodified liposomes, whereas the same liposomes were taken up only slightly by cells expressing CD44 proteins less. Competition assay using free HA or other polymers revealed that HA derivative-modified liposomes might be recognized by CD44. Therefore, HA-derivative-modified liposomes are useful as cell-specific intracellular drug delivery systems.

CD44 targeting hyaluronic acid coated lapatinib nanocrystals foster the efficacy against triple-negative breast cancer

Lapatinib (LPT) is an orally administered drug for the treatment of metastatic breast cancer. For expanding its therapeutic horizon, we have prepared its nanocrystals (LPT-NCs) that were subsequently coated with hyaluronic acid (HA) to produce LPT-HA-NCs. The detailed in-vitro and in-vivo investigation of LPT-HA-NCs showed the superior anticancer activity due to active targeting to CD44 receptors than the counterparts LPT-NCs and free LPT. In the triple negative 4T1 cells induced breast tumor bearing female Balb/C mice; LPT-HA-NCs treatment caused significant retardation of tumor growth and overall increase in animal survival probability because of their higher tumor localization, increased residence time. Our findings clearly suggest that HA coated LPT-NCs formulation enhances the activity of LPT against triple negative breast cancer. It exhibited magnificent therapeutic outcome at low dose thus presenting a strategy to reduce dose administrations and minimize dose related toxicity.

New developments and clinical transition of hyaluronic acid-based nanotherapeutics for treatment of cancer: reversing multidrug resistance, tumour-specific targetability and improved anticancer efficacy

This review aims to overview and critically analyses recent developments in achieving tumour-specific delivery of anticancer agents, maximizing anticancer efficacy, and mitigating tumour progression and off-target effects. Stemming from critical needs to develop target-specific delivery vehicles in cancer therapy, various hyaluronic acid (HA)-conjugated nanomedicines have been fabricated owing to their biocompatibility, safety, tumour-specific targetability of drugs and genes, and proficient interaction with cluster-determinant-44 (CD44) receptors over-expressed on the surface of tumour cells. HA-based conjugation or surface modulation of anticancer drugs encapsulated nanocarriers have shown promising efficacy against the various types of carcinomas of liver, breast, colorectal, pancreatic, lung, skin, ovarian, cervical, head and neck and gastric. The success of this emerging platform is assessed in achieving the rapid internalization of anticancer payloads into the tumour cells, impeding cancer cells division and proliferation, induction of cancer-specific apoptosis and prevention of metastasis (tumour progression). This review extends detailed insight into the engineering of HA-based nanomedicines, characterization, utilization for the diagnosis or treatment of CD44 over-expressing cancer subtypes and emphasizing the transition of nanomedicines to clinical cancer therapy.

Inhibition of Thioredoxin Reductase by Targeted Selenopolymeric Nanocarriers Synergizes the Therapeutic Efficacy of Doxorubicin in MCF7 Human Breast Cancer Cells

Increasing evidence suggests selenium nanoparticles (Se NPs) as potential cancer therapeutic agents and emerging drug delivery carriers, yet, the molecular mechanism of their anticancer activity still remains unclear. Recent studies indicate thioredoxin reductase (TrxR), a selenoenzyme, as a promising target for anticancer therapy. The present study explored the TrxR inhibition efficacy of Se NPs as a plausible factor impeding tumor growth. Hyaluronic acid (HA)-functionalized selenopolymeric nanocarriers (Se@CMHA NPs) were designed wielding chemotherapeutic potential for target specific Doxorubicin (DOX) delivery. Se@CMHA nanocarriers are thoroughly characterized asserting their chemical and physical integrity and possess prolonged stability. DOX-loaded selenopolymeric nanocarriers (Se@CMHA-DOX NPs) exhibited enhanced cytotoxic potential toward human cancer cells compared to free DOX in an equivalent concentration eliciting its selectivity. In first-of-its-kind findings, selenium as Se NPs in these polymeric carriers progressively inhibit TrxR activity, further augmenting the anticancer efficacy of DOX through a synergistic interplay between DOX and Se NPs. Detailed molecular studies on MCF7 cells also established that upon exposure to Se@CMHA-DOX NPs, MCF7 cells endure G2/M cell cycle arrest and p53-mediated caspase-independent apoptosis. To gauge the relevance of the developed nanosystem in in vivo settings, three-dimensional tumor sphere model mimicking the overall tumor environment was also performed, and the results clearly depict the effectiveness of our nanocarriers in reducing tumor activity. These findings are reminiscent of the fact that our Se@CMHA-DOX NPs could be a viable modality for effective cancer chemotherapy.

New molecular targets for functionalized nanosized drug delivery systems in personalized therapy for hepatocellular carcinoma

Hepatocellular carcinoma, the most frequent solid tumor of the liver, has a very poor prognosis, being the second most common cause of death from cancer worldwide. The incidence and mortality of this liver tumor are increasing in most areas of the world as a consequence of aging and the emerging of new risk factors such as the metabolic syndrome, beside the recognized role of hepatitis B and C viral infections and alcohol abuse. Despite the increasing knowledge on the molecular mechanisms underlying hepatic carcinogenesis, effective therapeutic strategies are still an unmet clinical need. Efforts have been made to develop selective drugs as well as effective targeted drug delivery systems. The development of novel drug carriers for therapeutic molecules can indeed offer a valuable strategy to ameliorate the efficacy of HCC treatment. In this review, we discuss recent drug delivery strategies for HCC treatment based on the exploitation of targeted nanoparticles (NPs). Indeed, a few of these platforms have achieved an advanced stage of preclinical development. Here, we review the most promising drug nanovehicles based on both synthetic and natural polymers, including polysaccharides that have emerged for their biocompatibility and biodegradability. To maximize site-selectivity and therapeutic efficacy, drug delivery systems should be functionalized with ligands which can specifically recognize and bind targets expressed by HCC, namely cell membrane associated antigens, receptors or biotransporters. Cell surface and intracellular molecular targets are exploited either to selectively deliver drug-loaded nanovehicles or to design novel selective therapeutics. In conclusion, the combination of novel and safe drug delivery strategies based on site-specific targeted drug nanovehicles with therapeutic molecular targets may significantly improve the pharmacological efficacy for the treatment of HCC.

Irinotecan and 5-fluorouracil-co-loaded, hyaluronic acid-modified layer-by-layer nanoparticles for targeted gastric carcinoma therapy

For targeted gastric carcinoma therapy, hyaluronic acid (HA)-modified layer-by-layer nanoparticles (NPs) are applied for improving anticancer treatment efficacy and reducing toxicity and side effects. The aim of this study was to develop HA-modified NPs for the co-loading of irinotecan (IRN) and 5-fluorouracil (5-FU). A novel polymer–chitosan (CH)–HA hybrid formulation (HA–CH–IRN/5-FU NPs) consisting of poly(d,l-lactide-co-glycolide) (PLGA) and IRN as the core, CH and 5-FU as a shell on the core and HA as the outmost layer was prepared. Its morphology, average size, zeta potential and drug encapsulation ability were evaluated. Human gastric carcinoma cells (MGC803 cells) and cancer-bearing mice were used for the testing of in vitro cytotoxicity and in vivo antitumor efficiency of NPs. HA–CH–IRN/5-FU NPs displayed enhanced antitumor activity in vitro and in vivo than non-modified NPs, single drug-loaded NPs and drugs solutions. The results demonstrate that HA–CH–IRN/5-FU NPs can achieve impressive antitumor activity and the novel targeted drug delivery system offers a promising strategy for the treatment of gastric cancer.

Nanocarrier based approaches for targeting breast cancer stem cells

Breast cancer stem cells (BCSCs) are heterogeneous subpopulation of tumour initiating cells within breast tumours. They are spared even after chemotherapy and responsible for tumour relapse. Targeting BCSCs is, therefore, necessary to achieve radical cure in breast cancer. Despite the availability of agents targeting BCSCs, their clinical application is limited due to their off-target effects and bioavailability issues. Nanotechnology based drug carriers (nanocarriers) offer various advantages to deliver anti-BCSCs agents specifically to their target sites by overcoming their bioavailability issues. In this review, we describe various strategies for targeting BCSCs using nanocarriers.

Nanomedicine applications in the treatment of breast cancer: current state of the art

Breast cancer is the most common malignant disease in women worldwide, but the current drug therapy is far from optimal as indicated by the high death rate of breast cancer patients. Nanomedicine is a promising alternative for breast cancer treatment. Nanomedicine products such as Doxil^® and Abraxane^® have already been extensively used for breast cancer adjuvant therapy with favorable clinical outcomes. However, these products were originally designed for generic anticancer purpose and not specifically for breast cancer treatment. With better understanding of the molecular biology of breast cancer, a number of novel promising nanotherapeutic strategies and devices have been developed in recent years. In this review, we will first give an overview of the current breast cancer treatment and the updated status of nanomedicine use in clinical setting, then discuss the latest important trends in designing breast cancer nanomedicine, including passive and active cancer cell targeting, breast cancer stem cell targeting, tumor microenvironment-based nanotherapy and combination nanotherapy of drug-resistant breast cancer. Researchers may get insight from these strategies to design and develop nanomedicine that is more tailored for breast cancer to achieve further improvements in cancer specificity, antitumorigenic effect, antimetastasis effect and drug resistance reversal effect.

Nanoparticle formulations to enhance tumor targeting of poorly soluble polyphenols with potential anticancer properties

Polyphenols have been extensively studied for their relevant anticancer activity. Quite often however their instability, extensive metabolization, low bioavailability and poor solubility limit their application in cancer prevention and therapy. Formulation in nanoparticles has been widely proposed as a means to overcome these limits, maximize localization and specific activity at tumor site. The present review is intended as an update of literature regarding nanoparticulate carriers aimed to deliver polyphenols to the cancer site. Three molecules were chosen, all of which were hydrophobic and poorly soluble, representative of different polyphenol classes: quercetin (QT) among the flavonoid group, curcumin (CUR) as representative of curcuminoids, and resveratrol (RSV) among the stilbenes. In particular, nanoparticulate systems suitable for poorly soluble drugs will be described and attention will be paid to characteristics designed to improve tumor targeting, specific delivery and interaction with tumor cells.

Secreted Frizzled-related protein 4 (sFRP4) chemo-sensitizes cancer stem cells derived from human breast, prostate, and ovary tumor cell lines

This study investigated molecular signals essential to sustain cancer stem cells (CSCs) and assessed their activity in the presence of secreted frizzled-related protein 4 (sFRP4) alone or in combination with chemotherapeutic drugs. SFRP4 is a known Wnt antagonist, and is also pro-apoptotic and anti-angiogenic. Additionally, sFRP4 has been demonstrated to confer chemo-sensitization and improve chemotherapeutic efficacy. CSCs were isolated from breast, prostate, and ovary tumor cell lines, and characterized using tumor-specific markers such as CD44⁺/CD24⁻/CD133⁺. The post-transcription data from CSCs that have undergone combinatorial treatment with sFRP4 and chemotherapeutic drugs suggest downregulation of stemness genes and upregulation of pro-apoptotic markers. The post-translational modification of CSCs demonstrated a chemo-sensitization effect of sFRP4 when used in combination with tumor-specific drugs. SFRP4 in combination with doxorubicin/cisplatin reduced the proliferative capacity of the CSC population in vitro. Wnt/β-catenin signaling is important for proliferation and self-renewal of CSCs in association with human tumorigenesis. The silencing of this signaling pathway by the application of sFRP4 suggests potential for improved in vivo chemo-responses.

Transcription activator, hyaluronic acid and tocopheryl succinate multi-functionalized novel lipid carriers encapsulating etoposide for lymphoma therapy

Delivery of chemotherapeutic drugs using nanocarriers is emerging as a promising approach for the treatment of cancer. The aim of this research was to develop a dual targeted d-α-tocopheryl succinate (TOS) functionalized nanostructured lipid carriers (NLCs), using etoposide (ETP) as a model drug to prove their in vitro and in vivo anti-tumor effects. Novel ETP loaded NLCs were constructed (ETP-NLCs). Hyaluronic acid (HA) and cell-penetrating peptide transcription activator (TAT) was applied for the surface decoration of ETP NLCs (HATOS/TATTOS-ETP-NLCs). The antitumor efficiency of HATOS/TATTOS-ETP-NLCs was evaluated in tumor bearing animal models. HATOS/TATTOS-ETP-NLCs displayed significantly higher transfection efficiency and better antitumor ability than undecorated ETP-NLCs in lymphoma cells bearing mice model. The newly constructed NLCs could successfully load drug and gene; and TAT could function as excellent targeting ligands to improve the cell targeting ability of the gene loaded nanocarriers. The resulting dual ligands decorated vectors could be a promising targeted gene delivery system for the lymphoma treatment.

Recent advances in hyaluronic acid-decorated nanocarriers for targeted cancer therapy

The cluster-determinant 44 (CD44) receptor has a high affinity for hyaluronic acid (HA) binding and is a desirable receptor for active targeting based on its overexpression in cancer cells compared with normal body cells. The nanocarrier affinity can be increased by conjugating drug-loaded carriers with HA, allowing enhanced cancer cell uptake via the HA-CD44 receptor-mediated endocytosis pathway. In this review, we discuss recent advances in HA-based nanocarriers and micelles for cancer therapy. In vitro and in vivo experiments have repeatedly indicated HA-based nanocarriers to be a target-specific drug and gene delivery platform with great promise for future applications in clinical cancer therapy.

Cancer stem cell metabolism: a potential target for cancer therapy

Cancer Stem cells (CSCs) are a unipotent cell population present within the tumour cell mass. CSCs are known to be highly chemo-resistant, and in recent years, they have gained intense interest as key tumour initiating cells that may also play an integral role in tumour recurrence following chemotherapy. Cancer cells have the ability to alter their metabolism in order to fulfil bio-energetic and biosynthetic requirements. They are largely dependent on aerobic glycolysis for their energy production and also are associated with increased fatty acid synthesis and increased rates of glutamine utilisation. Emerging evidence has shown that therapeutic resistance to cancer treatment may arise due to dysregulation in glucose metabolism, fatty acid synthesis, and glutaminolysis. To propagate their lethal effects and maintain survival, tumour cells alter their metabolic requirements to ensure optimal nutrient use for their survival, evasion from host immune attack, and proliferation. It is now evident that cancer cells metabolise glutamine to grow rapidly because it provides the metabolic stimulus for required energy and precursors for synthesis of proteins, lipids, and nucleic acids. It can also regulate the activities of some of the signalling pathways that control the proliferation of cancer cells.

This review describes the key metabolic pathways required by CSCs to maintain a survival advantage and highlights how a combined approach of targeting cellular metabolism in conjunction with the use of chemotherapeutic drugs may provide a promising strategy to overcome therapeutic resistance and therefore aid in cancer therapy.

Hyaluronic Acid and Its Derivatives in Coating and Delivery Systems: Applications in Tissue Engineering, Regenerative Medicine and Immunomodulation

As an Extracellular Matrix (ECM) component, Hyaluronic acid (HA) plays a multi-faceted role in cell migration, proliferation and differentiation at micro level and system level events such as tissue water homeostasis. Among its biological functions, it is known to interact with cytokines and contribute to their retention in ECM microenvironment. In addition to its biological functions, it has advantageous physical properties which result in the industrial endeavors in the synthesis and extraction of HA for variety of applications ranging from medical to cosmetic. Recently, HA and its derivatives have been the focus of active research for applications in biomedical device coatings, drug delivery systems and in the form of scaffolds or cell-laden hydrogels for tissue engineering. A specific reason for the increase in use of HA based structures is their immunomodulatory and regeneration inducing capacities. In this context, this article reviews recent literature on modulation of the implantable biomaterial microenvironment by systems based on HA and its derivatives, particularly hydrogels and microscale coatings that are able to deliver cytokines in order to reduce the adverse immune reactions and promote tissue healing.

Improving Targeting of Metal-Phenolic Capsules by the Presence of Protein Coronas

Particles adsorb proteins when they enter a physiological environment; this results in a surface coating termed a "protein corona". A protein corona can affect both the properties and functionalities of engineered particles. Here, we prepared hyaluronic acid (HA)-based capsules through the assembly of metal-phenolic networks (MPNs) and engineered their targeting ability in the absence and presence of protein coronas by varying the HA molecular weight. The targeting ability of the capsules was HA molecular weight dependent, and a high HA molecular weight (>50 kDa) was required for efficient targeting. The specific interactions between high molecular weight HA capsules and receptor-expressing cancer cells were negligibly affected by the presence of protein coronas, whereas nonspecific capsule-cell interactions were significantly reduced in the presence of a protein corona derived from human serum. Consequently, the targeting specificity of HA-based MPN capsules was enhanced due to the formation of a protein corona. This study highlights the significant and complex roles of a protein corona in biointeractions and demonstrates how protein coronas can be used to improve the targeting specificity of engineered particles.