Hyaluronic acid conjugates as vectors for the active targeting of drugs, genes and nanocomposites in cancer treatment

Emerging natural polymer-based architectured nanotherapeutics for the treatment of cancer

The field of cancer therapy is advancing rapidly, placing a crucial emphasis on innovative drug delivery systems. The increasing global impact of cancer highlights the need for creative therapeutic strategies. Natural polymer-based nanotherapeutics have emerged as a captivating avenue in this pursuit, drawing substantial attention due to their inherent attributes. These attributes include biodegradability, biocompatibility, negligible toxicity, extended circulation time, and a wide range of therapeutic payloads. The unique size, shape, and morphological characteristics of these systems facilitate profound tissue penetration, complementing active and passive targeting strategies. Moreover, these nanotherapeutics exploit specific cellular and subcellular trafficking pathways, providing precise control over drug release kinetics. This comprehensive review emphasizes the utilization of naturally occurring polymers such as polysaccharides (e.g., chitosan, hyaluronic acid, alginates, dextran, and cyclodextrin) and protein-based polymers (e.g., ferritin, gelatin, albumin) as the foundation for nanoparticle development. The paper meticulously examines their in vitro characteristics alongside in vivo efficacy, particularly focusing on their pivotal role in ameliorating diverse types of solid tumors within cancer therapy. The amalgamation of material science ingenuity and biological insight has led to the formulation of these nanoparticles, showcasing their potential to reshape the landscape of cancer treatment.

Dual-targeting CD44 and mucin by hyaluronic acid and 5TR1 aptamer for epirubicin delivery into cancer cells: Synthesis, characterization, in vitro and in vivo evaluation

One of the revolutionized cancer treatment is active targeting nanomedicines. This study aims to create a dual-targeted drug delivery system for Epirubicin (EPI) to cancer cells. Hyaluronic acid (HA) is the first targeting ligand, and 5TR1 aptamer (5TR1) is the second targeting ligand to guide the dual-targeted drug delivery system to the cancer cells. HA is bound to highly expressed receptors like CD44 on cancer cells. 5TR1, DNA aptamer, is capable of recognizing MUC1 glycoprotein, which is overexpressed in cancer cells. The process involved binding EPI and 5TR1 to HA using adipic acid dihydrazide (AA) as a linker. The bond between the components was confirmed using 1H NMR. The binding of 5TR1 to HA-AA-EPI was confirmed using gel electrophoresis. The particle size (132.6 ± 9 nm) and Zeta Potential (-29 ± 4.4 mV) were measured for the final nanoformulation (HA-AA-EPI-5TR1). The release of EPI from the HA-AA-EPI-5TR1 nanoformulation was also studied at different pH levels. In the acidic pH (5.4 and 6.5) release pattern of EPI from the HA-AA-EPI-5TR1 nanoformulation was higher than physiological pH (7.4). The cytotoxicity and cellular uptake of the synthetic nanoformula were evaluated using MTT and flow cytometry analysis. Flow cytometry and cellular cytotoxicity studies were exhibited in a negative MUC1-cell line (CHO) and two positive MUC1+cell lines (MCF-7 and C26). Results confirmed that there is a notable contrast between the dual-targeted (HA-AA-EPI-5TR1) and single-targeted (HA-AA-EPI) nanoformulation in MCF-7 and C26 cell lines (MUC1+). In vivo studies showed that HA-AA-EPI-5TR1 nanoformulation has improved efficiency with limited side effect in C26 tumor-bearing mice. Also, Fluorescence imaging and pathological evaluation showed reduced side effects in the heart tissue of mice receiving HA-AA-EPI-5TR1 than free EPI. So, this targeted approach effectively delivers EPI to cancer cells with reduced side effects.

The Hyaluronan/CD44 Axis: A Double-Edged Sword in Cancer

Hyaluronic acid (HA) receptor CD44 is widely used for identifying cancer stem cells and its activation promotes stemness. Recent evidence shows that overexpression of CD44 is associated with poor prognosis in most human cancers and mediates therapy resistance. For these reasons, in recent years, CD44 has become a treatment target in precision oncology, often via HA-conjugated antineoplastic drugs. Importantly, HA molecules of different sizes have a dual effect and, therefore, may enhance or attenuate the CD44-mediated signaling pathways, as they compete with endogenous HA for binding to the receptors. The magnitude of these effects could be crucial for cancer progression, as well as for driving the inflammatory response in the tumor microenvironment. The increasingly common use of HA-conjugated drugs in oncology, as well as HA-based compounds as adjuvants in cancer treatment, adds further complexity to the understanding of the net effect of hyaluronan-CD44 activation in cancers. In this review, I focus on the significance of CD44 in malignancy and discuss the dichotomous function of the hyaluronan/CD44 axis in cancer progression.

Hyaluronan hydrates and compartmentalises the CNS/PNS extracellular matrix and provides niche environments conducive to the optimisation of neuronal activity

The central nervous system/peripheral nervous system (CNS/PNS) extracellular matrix is a dynamic and highly interactive space-filling, cell-supportive, matrix-stabilising, hydrating entity that creates and maintains tissue compartments to facilitate regional ionic micro-environments and micro-gradients that promote optimal neural cellular activity. The CNS/PNS does not contain large supportive collagenous and elastic fibrillar networks but is dominated by a high glycosaminoglycan content, predominantly hyaluronan (HA) and collagen is restricted to the brain microvasculature, blood-brain barrier, neuromuscular junction and meninges dura, arachnoid and pia mater. Chondroitin sulphate-rich proteoglycans (lecticans) interactive with HA have stabilising roles in perineuronal nets and contribute to neural plasticity, memory and cognitive processes. Hyaluronan also interacts with sialoproteoglycan associated with cones and rods (SPACRCAN) to stabilise the interphotoreceptor matrix and has protective properties that ensure photoreceptor viability and function is maintained. HA also regulates myelination/re-myelination in neural networks. HA fragmentation has been observed in white matter injury, multiple sclerosis, and traumatic brain injury. HA fragments (2 × 105  Da) regulate oligodendrocyte precursor cell maturation, myelination/remyelination, and interact with TLR4 to initiate signalling cascades that mediate myelin basic protein transcription. HA and its fragments have regulatory roles over myelination which ensure high axonal neurotransduction rates are maintained in neural networks. Glioma is a particularly invasive brain tumour with extremely high mortality rates. HA, CD44 and RHAMM (receptor for HA-mediated motility) HA receptors are highly expressed in this tumour. Conventional anti-glioma drug treatments have been largely ineffective and surgical removal is normally not an option. CD44 and RHAMM glioma HA receptors can potentially be used to target gliomas with PEP-1, a cell-penetrating HA-binding peptide. PEP-1 can be conjugated to a therapeutic drug; such drug conjugates have successfully treated dense non-operative tumours in other tissues, therefore similar applications warrant exploration as potential anti-glioma treatments.

Marine Biomaterials: Hyaluronan

The marine-derived hyaluronic acid and other natural biopolymers offer exciting possibilities in the field of biomaterials, providing sustainable and biocompatible alternatives to synthetic materials. Their unique properties and abundance in marine sources make them valuable resources for various biomedical and industrial applications. Due to high biocompatible features and participation in biological processes related to tissue healing, hyaluronic acid has become widely used in tissue engineering applications, especially in the wound healing process. The present review enlightens marine hyaluronan biomaterial providing its sources, extraction process, structures, chemical modifications, biological properties, and biocidal applications, especially for wound healing/dressing purposes. Meanwhile, we point out the future development of wound healing/dressing based on hyaluronan and its composites and potential challenges.

Curvilinear regression analysis of benzenoid hydrocarbons and computation of some reduced reverse degree based topological indices for hyaluronic acid-paclitaxel conjugates

Graph theoretical molecular descriptors alias topological indices are a convenient means for expressing in numerical form the chemical structure encoded in a molecular graph. The structure descriptors derived from molecular graphs are widely used in quantitative structure-property relationship (QSPR) and quantitative structure-activity relationship (QSAR) studies. The reason for introducing new indices is to obtain predictions of target properties of considered molecules that are better than the predictions obtained using already known indices. In this paper, we apply the reduced reverse degree based indices introduced in 2021 by Vignesh et al. In the QSPR analysis, we first compute the reduced reverse degree based indices for a family of benzenoid hydrocarbon molecules and then we obtain the correlation with the Physico-chemical properties of the considered molecules. We show that all the properties taken into consideration for the benzenoid hydrocarbons can be very effectively predicted by the reduced reverse degree based indices. Also, we have compared the predictive capability of reduced reverse degree based topological descriptors against 16 existing degree based indices. Further, we compute the defined reduced reverse degree based topological indices for Hyaluronic Acid-Paclitaxel Conjugates [Formula: see text], [Formula: see text].

Hyaluronan-Cyclodextrin Conjugates as Doxorubicin Delivery Systems

In the last years, nanoparticles based on cyclodextrins have been widely investigated for the delivery of anticancer drugs. In this work, we synthesized nanoparticles with a hyaluronic acid backbone functionalized with cyclodextrins under green conditions. We functionalized hyaluronic acid with two different molecular weights (about 11 kDa and 45 kDa) to compare their behavior as doxorubicin delivery systems. We found that the new hyaluronan-cyclodextrin conjugates increased the water solubility of doxorubicin. Moreover, we tested the antiproliferative activity of doxorubicin in the presence of the new cyclodextrin polymers in SK-N-SH and SK-N-SH-PMA (over-expressing CD44 receptor) cancer cells. We found that hyaluronan-cyclodextrin conjugates improved the uptake and antiproliferative activity of doxorubicin in the SK-N-SH-PMA compared to the SK-N-SH cell line at the ratio 8/1 doxorubicin/polymer. Notably, the system based on hyaluronan (45 kDa) was more effective as a drug carrier and significantly reduced the IC₅₀ value of doxorubicin by about 56%. We also found that hyaluronic acid polymers determined an improved antiproliferative activity of doxorubicin (IC₅₀ values are on average reduced by about 70% of free DOXO) in both cell lines at the ratio 16/1 doxorubicin/polymer.

Nontoxic Natural Polymeric Particle Vehicles Derived from Hyaluronic Acid and Mannitol as Mitomycin C Carriers for Bladder Cancer Treatment

Hyaluronic acid/mannitol (HA/MN)-based particles were designed as mitomycin c (MMC) delivery vehicles through the crosslinking of 1:0, 3:1, 1:3, and 0:1 mole ratios of HA/MN to investigate their potential use in bladder cancer therapy. The HA/MN-MMC particles prepared by the microemulsion crosslinking method were of 0.5-10 μm size with a zeta potential value of -36.7 mV. The MMC carrier potential of the HA/MN-MMC particles was investigated by changing HA/MN ratios in the particle structure. The MMC loading capacity of neat HA particles was 5.3 ± 1.1 mg/g, whereas HA/MN (1:3) particles could be loaded with about three times more drug, for example, 18.4 ± 0.8 mg/g. The kinetic of MMC drug delivery from the HA/MN-MMC particles were tested in vitro in bladder cancer conditions for example, pH 4.5, 6, and 7.4. The HA-MMC particles released approximately 70% of the loaded drug in 300 h, while 43% of the loaded drug was released from the HA/MN-MMC particles within 600 h under physiological conditions, pH 7.4, 37 °C. The cytotoxicity of HA-based particles on healthy L929 fibroblast cells and HTB-9 human bladder cancer cells was investigated in vitro via MTT tests. Bare MMC inhibited about 90% of L929 fibroblast cells even at 100 μg/mL, but the cell viabilities in the presence of HA-MMC and HA/MN-MMC particles were 85 ± 5 and 109 ± 7% at 1000 μg/mL, respectively. The HA/MN-MMC (1:3) particles at 1000 μg/mL were found capable of destroying half of HTB-9 human bladder cancer cells within 24 h. Interestingly, the same particles at 50 μg/mL destroyed almost all the cancer cells with 8 ± 5% cell viability in 72 h of incubation time. The designed HA/MN-MMC (1:3) particles were found to afford a chemotherapeutic effect on the tumor cancers while reducing the toxicity of MMC against L929 fibroblast cells.

The Superiority of Bacillus megaterium over Escherichia coli as a Recombinant Bacterial Host for Hyaluronic Acid Production

(1) Background: Hyaluronic acid (HA) is a polyanionic mucopolysaccharide extensively used in biomedical and cosmetic industries due to its unique rheological properties. Recombinant HA production using other microbial platforms has received increasing interest to avoid potential toxin contamination associated with its production by streptococcal fermentation. In this study, the Gram-negative strains Escherichia coli (pLysY/Iq), E. coli Rosetta2, E. coli Rosetta (DE3) pLysS, E. coli Rosetta2 (DE3), E. coli Rosetta gammiB(DE3)pLysS, and the Gram-positive Bacillus megaterium (MS941) were investigated as new platforms for the heterologous production of HA. (2) Results: The HA biosynthesis gene hasA, cloned from Streptococcus equi subsp. zoopedemicus, was ligated into plasmid pMM1522 (MoBiTec), resulting in pMM1522 hasA, which was introduced into E. coli Rosetta-2(DE3) and B. megaterium (MS941). The initial HA titer by the two hosts in the LB medium was 5 mg/L and 50 mg/L, respectively. Streptococcal hasABC and hasABCDE genes were ligated into plasmid pPT7 (MoBiTec) and different E. coli host strains were then transformed with the resulting plasmids pPT7hasABC and pPT7hasABCDE. For E. coli Rosetta-gamiB(DE3)pLysS transformed with pPT7hasABC, HA production was 500 ± 11.4 mg/L in terrific broth (TB) medium. Productivity was slightly higher (585 ± 2.9 mg/L) when the same host was transformed with pPT7 carrying the entire HA operon. We also transformed B. megaterium (MS941) protoplasts carrying T7-RNAP with pPT7hasABC and pPT7hasABCDE. In comparison, the former plasmid resulted in HA titers of 2116.7 ± 44 and 1988.3 ± 19.6 mg/L in LB media supplemented with 5% sucrose and A5 medium + MOPSO, respectively; the latter plasmid boosted the titer final concentration further to reach 2476.7 ± 14.5 mg/L and 2350 ± 28.8 mg/L in the two media, respectively. The molecular mass of representative HA samples ranged from 105 − 106 Daltons (Da), and the polydispersity index (PDI) was <2. Fourier transform infrared spectroscopy (FTIR) spectra of the HA product were identical to those obtained for commercially available standard polymers. Finally, scanning electron microscopic examination revealed the presence of extensive HA capsules in E. coli Rosetta-gamiB(DE3)pLysS, while no HA capsules were produced by B. megaterium. (3) Conclusions: Our results suggested that Gram-positive bacteria are probably superior host strains for recombinant HA production over their Gram-negative counters. The titers and the molecular weight (MW) of HA produced by B. megaterium were significantly higher than those obtained by different E. coli host strains used in this study.

Studies on the partial characterization of extracted glycosaminoglycans from fish waste and its potentiality in modulating obesity through in-vitro and in-vivo

Glycosaminoglycans (GAGs) are bioactive polysaccharides or glycoconjugates found in the fish waste having significant health impacts. In the present study it has been attempted to extract GAGs from mackerel fish waste through chemical and enzymatic methods. Further, the extracted GAGs (e-GAGs) were analyzed for their composition (uronic acid, total sugar & sulfate), chemical characterization was carried out through techniques of scanning electron microscopy (SEM) and Fourier transform infrared spectroscopy (FTIR) & Proton NMR. Further, probable major GAGs present was identified by enzymatic digestion. The biological potential of the extracted glycoconjugate was assessed further through in-vitro and in-vivo studies. In-vitro biological activity showed good lipase inhibition (IC₅₀, 2.6 mg/mL) and bile acid binding properties (dose-dependent). Lipid accumulation lowered in the e-GAGs differentiated 3T3L1 preadipocyte cells have also been observed. The high fat fed animal (in-vivo) study showed ameliorative effect via reducing blood sugar∼1.28↓, lipid profile↓, plasma insulin∼3.5↓, improved glucose tolerance, and homeostatic model assessment for insulin resistance (HOMA-IR, ∼3.0↓). Furthermore, elimination of bile acid (BA) due to GAG-BA binding properties resultant in removal of elevated fecal triglyceride and cholesterol suggesting its lipid lowering activity. Regulation of various proteins linked to carbohydrate and lipid metabolism including fatty acid synthase (FAS), low density lipoproteins receptor (LDL-R), 7α-hydroxylase, glucose transporter-4 (GLUT4) and Peroxisome proliferator- activated receptor gamma (PPAR-γ) were significant (p < 0.05) with e-GAGs treatment when compared to HFD group. Thus, the e-GAGs showed potential hypolipidemic activity through elimination of bile acid binding property together with regulating the specific protein related to obesity and its associated complications.

Recent development of a magneto-optical nanoplatform for multimodality imaging of pancreatic ductal adenocarcinoma

Pancreatic ductal adenocarcinoma (PDAC) is the most common type of pancreatic cancer. Given its inconspicuous and atypical early symptoms and hidden location, most patients have already reached the terminal stage before diagnosis. At present, the diagnosis of PDAC mainly depends on serological and imaging examinations. However, serum tests cannot identify specific tumor locations and each imaging technology has its own defects, bringing great challenges to the early diagnosis of PDAC. Therefore, it is of great significance to find new strategies for the early and accurate diagnosis of PDAC. In recent years, a magneto-optical nanoplatform integrating near infrared fluorescence, photoacoustic, magnetic resonance imaging, etc. has attracted widespread attention, giving full play to the complementary advantages of each imaging modality. Herein, we summarize the recent advances of imaging modalities in the diagnosis of pancreatic cancer, and then discuss in detail the construction and modification of magneto or/and optical probes for multimodal imaging, and advances in early diagnosis using the combination of various imaging modalities, which can provide potential tools for the early diagnosis or even intraoperative navigation and post-treatment follow-up of PDAC patients.

Cancer Cytotoxicity of a Hybrid Hyaluronan-Superparamagnetic Iron Oxide Nanoparticle Material: An In-Vitro Evaluation

While hyaluronic acid encapsulating superparamagnetic iron oxide nanoparticles have been reported to exhibit selective cytotoxicity toward cancer cells, it is unclear whether low-molecular-weight hyaluronic acid-conjugated superparamagnetic iron oxide nanoparticles also display such cytotoxicity. In this study, high-molecular-weight hyaluronic acid was irradiated with γ-ray, while Fe3O4 nanoparticles were fabricated using chemical co-precipitation. The low-molecular-weight hyaluronic acid and Fe3O4 nanoparticles were then combined according to a previous study. Size distribution, zeta potential, and the binding between hyaluronic acid and iron oxide nanoparticles were examined using dynamic light scattering and a nuclear magnetic resonance spectroscopy. The ability of the fabricated low-molecular-weight hyaluronic acid conjugated superparamagnetic iron oxide nanoparticles to target cancer cells was examined using time-of-flight secondary ion mass spectrometry and T2* weighted magnetic resonance images to compare iron signals in U87MG human glioblastoma and NIH3T3 normal fibroblast cell lines. Comparison showed that the present material could target U87MG cells at a higher rate than NIH3T3 control cells, with a viability inhibition rate of 34% observed at day two and no cytotoxicity observed in NIH3T3 normal fibroblasts during the three-day experimental period. Supported by mass spectrometry images confirming that the nanoparticles accumulated on the surface of cancer cells, the fabricated materials can reasonably be suggested as a candidate for both magnetic resonance imaging applications and as an injectable anticancer agent.

CD44-Targeted Carriers: The Role of Molecular Weight of Hyaluronic Acid in the Uptake of Hyaluronic Acid-Based Nanoparticles

Nanotechnology offers advanced biomedical tools for diagnosis and drug delivery, stressing the value of investigating the mechanisms by which nanocarriers interact with the biological environment. Herein, the cellular response to CD44-targeted nanoparticles (NPs) was investigated. CD44, the main hyaluronic acid (HA) receptor, is widely exploited as a target for therapeutic purposes. HA NPs were produced by microfluidic platform starting from HA with different molecular weights (Mw, 280, 540, 820 kDa) by polyelectrolyte complexation with chitosan (CS). Thanks to microfluidic technology, HA/CS NPs with the same physical features were produced, and only the effects of HA Mw on CD44-overexpressing cells (human mesenchymal stem cells, hMSCs) were studied. This work provides evidence of the HA/CS NPs biocompatibility regardless the HA Mw and reveals the effect of low Mw HA in improving the cell proliferation. Special attention was paid to the endocytic mechanisms used by HA/CS NPs to enter hMSCs. The results show the notable role of CD44 and the pronounced effect of HA Mw in the NPs’ internalization. HA/CS NPs uptake occurs via different endocytic pathways simultaneously, and most notably, NPs with 280 kDa HA were internalized by clathrin-mediated endocytosis. Instead, NPs with 820 kDa HA revealed a greater contribution of caveolae and cytoskeleton components.

Construction of a dual-responsive dual-drug delivery platform based on the hybrids of mesoporous silica, sodium hyaluronate, chitosan and oxidized sodium carboxymethyl cellulose

An intelligent drug delivery platform based on the hybrids of mesoporous silica nanoparticles (MSN), sodium hyaluronate (HA), chitosan (CS) and oxidized sodium carboxymethyl cellulose (oxCMC) is developed, which can be used for dual-responsive dual-drug delivery. Hydrophilic cytarabine (Cyt) is first loaded into the mesopores of the aminated MSN (NH₂-MSN), which is encapsulated by the hydrogel of HA and cystamine (Cys) crosslinked via amidation. The Cyt encapsulated hydrogel which is denoted as Cyt/NH₂-MSN/HA is co-encapsulated with hydrophobic methotrexate (MTX) into the hydrogel of CS and oxCMC resulted from Schiff base reaction. Since the acylhydrazone bonds (-HC=N-) between CS and oxCMC are sensitive to pH and the disulfide bonds (-S-S-) in Cys are sensitive to glutathione (GSH), the resultant dual-drug encapsulated hydrogel, denoted as Cyt/NH₂-MSN/HA/MTX/CS/oxCMC, can be used for dual-responsive (pH and GSH) drug delivery. The results of cell viability demonstrate that the developed dual-drug encapsulated hydrogel has significantly higher efficacy of chemotherapy than that of single-drug (MTX or Cyt) encapsulated hydrogel.

Hyaluronic acid-based drug nanocarriers as a novel drug delivery system for cancer chemotherapy: A systematic review

Chemotherapy is the most common treatment strategy for cancer patients. Nevertheless, limited drug delivery to cancer cells, intolerable toxicity, and multiple drug resistance are constant challenges of chemotherapy. Novel targeted drug delivery strategies by using nanoparticles have attracted much attention due to reducing side effects and increasing drug efficacy. Therefore, the most important outcome of this study is to answer the question of whether active targeted HA-based drug nanocarriers have a significant effect on improving drug delivery to cancer cells.This study aimed to systematically review studies on the use of hyaluronic acid (HA)-based nanocarriers for chemotherapy drugs. The two databases MagIran and SID from Persian databases as well as international databases PubMed, WoS, Scopus, Science Direct, Embase, as well as Google Scholar were searched for human studies and cell lines and/or xenograft mice published without time limit until 2020. Keywords used to search included Nanoparticle, chemotherapy, HA, Hyaluronic acid, traditional medicine, natural medicine, chemotherapeutic drugs, natural compound, cancer treatment, and cancer. The quality of the studies was assessed by the STROBE checklist. Finally, studies consistent with inclusion criteria and with medium- to high-quality were included in the systematic review.According to the findings of studies, active targeted HA-based drug nanocarriers showed a significant effect on improving drug delivery to cancer cells. Also, the use of lipid nanoparticles with a suitable coating of HA have been introduced as biocompatible drug carriers with high potential for targeted drug delivery to the target tissue without affecting other tissues and reducing side effects. Enhanced drug delivery, increased therapeutic efficacy, increased cytotoxicity and significant inhibition of tumor growth, as well as high potential for targeted chemotherapy are also reported to be benefits of using HA-based nanocarriers for tumors with increased expression of CD44 receptor.

Fluorescent nanodiamond - hyaluronate conjugates for target-specific molecular imaging

Despite wide investigation on molecular imaging contrast agents, there are still strong unmet medical needs to enhance their signal-to background ratio, brightness, photostability, and biocompatibility with multimodal imaging capability. Here, we assessed the feasibility of fluorescent nanodiamonds (FNDs) as carbon based photostable and biocompatible materials for molecular imaging applications. Because FNDs have negatively charged nitrogen vacancy (NV) centers, they can emit bright red light. FNDs were conjugated to hyaluronate (HA) for target-specific molecular imaging. HA is a biocompatible, biodegradable, and linear polysaccharide with abundant HA receptors in the liver, enabling liver targeted molecular imaging. In vitro cell viability tests revealed the biocompatibility of HA-FND conjugates and the competitive cellular uptake test confirmed their target-specific intracellular delivery to HepG2 cells with HA receptors. In addition, in vivo fluorescence lifetime (FLT) assessment revealed the imaging capability of FNDs and HA-FND conjugates. After that, we could confirm the statistically significant liver-targeted delivery of HA-FND conjugates by in vivo imaging system (IVIS) analysis and ex vivo biodistribution tests in various organs. The renal clearance test and histological analysis corroborated the in vivo biocompatibility and safety of HA-FND conjugates. All these results demonstrated the feasibility of HA-FND conjugates for further molecular imaging applications.

Lignin, lipid, protein, hyaluronic acid, starch, cellulose, gum, pectin, alginate and chitosan-based nanomaterials for cancer nanotherapy: Challenges and opportunities

Although nanotechnology-driven drug delivery systems are relatively new, they are rapidly evolving since the nanomaterials are deployed as effective means of diagnosis and delivery of assorted therapeutic agents to targeted intracellular sites in a controlled release manner. Nanomedicine and nanoparticulate drug delivery systems are rapidly developing as they play crucial roles in the development of therapeutic strategies for various types of cancer and malignancy. Nevertheless, high costs, associated toxicity and production of complexities are some of the critical barriers for their applications. Green nanomedicines have continually been improved as one of the viable approaches towards tumor drug delivery, thus making a notable impact on which considerably affect cancer treatment. In this regard, the utilization of natural and renewable feedstocks as a starting point for the fabrication of nanosystems can considerably contribute to the development of green nanomedicines. Nanostructures and biopolymers derived from natural and biorenewable resources such as proteins, lipids, lignin, hyaluronic acid, starch, cellulose, gum, pectin, alginate, and chitosan play vital roles in the development of cancer nanotherapy, imaging and management. This review uncovers recent investigations on diverse nanoarchitectures fabricated from natural and renewable feedstocks for the controlled/sustained and targeted drug/gene delivery systems against cancers including an outlook on some of the scientific challenges and opportunities in this field. Various important natural biopolymers and nanomaterials for cancer nanotherapy are covered and the scientific challenges and opportunities in this field are reviewed.

Hyaluronic acid prodrug micelles for tumour therapy

Hyaluronic acid (HA), an important component of the extracellular matrix, has high water solubility and biocompatibility, and good application prospects in biomedicine. Especially in tumour treatment, prodrug polymer micelles prepared from HA and chemotherapeutics can increase water solubility, prolong drug release time, improve organ distribution and therapeutic effects, and show good tumour targeting and biocompatibility. Therefore, this study introduces strategies for using HA to prepare prodrug polymer micelles and discusses recent research on HA prodrug micelles for antitumor applications.

Is hyaluronic acid the perfect excipient for the pharmaceutical need?

Hyaluronic acid has become an interesting and important polymer as an excipient for pharmaceutical products due to its beneficial properties, like solubility, biocompatibility and biodegradation. To improve the properties of hyaluronic acid, different possibilities for chemical modifications are presented, and the opportunities as novel systems for drug delivery are discussed. This review gives an overview over the production of hyaluronic acid, the possibilities of its chemical modification and the current state of in vitro and in vivo research. Furthermore, market approved and commercially available products are reviewed and derivatives undergoing clinical trials and applying for market approval are shown. In particular, hyaluronic acid has been studied for different administrations in rheumatology, ophthalmology, local anesthetics, cancer treatment and bioengineering of tissues. The present work concludes with perspectives for future administration of pharmaceuticals based on hyaluronic acid.

Marine Exopolysaccharide Complexed With Scandium Aimed as Theranostic Agents

(1) Background: Exopolysaccharide (EPS) derivatives, produced by Alteromonas infernus bacterium, showed anti-metastatic properties. They may represent a new class of ligands to be combined with theranostic radionuclides, such as ⁴⁷Sc/⁴⁴Sc. The goal of this work was to investigate the feasibility of such coupling. (2) Methods: EPSs, as well as heparin used as a drug reference, were characterized in terms of molar mass and dispersity using Asymmetrical Flow Field-Flow Fractionation coupled to Multi-Angle Light Scattering (AF4-MALS). The intrinsic viscosity of EPSs at different ionic strengths were measured in order to establish the conformation. To determine the stability constants of Sc with EPS and heparin, a Free-ion selective radiotracer extraction (FISRE) method has been used. (3) Results: AF4-MALS showed that radical depolymerization produces monodisperse EPSs, suitable for therapeutic use. EPS conformation exhibited a lower hydrodynamic volume for the highest ionic strengths. The resulting random-coiled conformation could affect the complexation with metal for high concentration. The LogK of Sc-EPS complexes have been determined and showing that they are comparable to the Sc-Hep. (4) Conclusions: EPSs are very promising to be coupled with the theranostic pair of scandium for Nuclear Medicine.

Stability Evaluation and Degradation Studies of DAC® Hyaluronic-Polylactide Based Hydrogel by DOSY NMR Spectroscopy

The stability and the degradation of polymers in physiological conditions are very important issues in biomedical applications. The copolymer of hyaluronic acid and poly-D,L-lactic acid (made available in a product called DAC®) produces a hydrogel which retains the hydrophobic character of the poly-D,L-lactide sidechains and the hydrophilic character of a hyaluronic acid backbone. This hydrogel is a suitable device for the coating of orthopedic implants with structured surfaces. In fact, this gel creates a temporary barrier to bacterial adhesion by inhibiting colonization, thus preventing the formation of the biofilm and the onset of an infection. Reabsorbed in about 72 h after the implant, this hydrogel does not hinder bone growth processes. In the need to assess stability and degradation of both the hyaluronan backbone and of the polylactic chains along time and temperature, we identified NMR spectroscopy as a privileged technique for the characterization of the released species, and we applied diffusion-ordered NMR spectroscopy (DOSY-NMR) for the investigation of molecular weight dispersion. Our diffusion studies of DAC® in physiological conditions provided a full understanding of the product degradation by overcoming the limitations observed in applying classical chromatography approaches by gel permeation UV.

Microbial Exopolysaccharides as Drug Carriers

Microbial exopolysaccharides are peculiar polymers that are produced by living organisms and protect them against environmental factors. These polymers are industrially recovered from the medium culture after performing a fermentative process. These materials are biocompatible and biodegradable, possessing specific and beneficial properties for biomedical drug delivery systems. They can have antitumor activity, they can produce hydrogels with different characteristics due to their molecular structure and functional groups, and they can even produce nanoparticles via a self-assembly phenomenon. This review studies the potential use of exopolysaccharides as carriers for drug delivery systems, covering their versatility and their vast possibilities to produce particles, fibers, scaffolds, hydrogels, and aerogels with different strategies and methodologies. Moreover, the main properties of exopolysaccharides are explained, providing information to achieve an adequate carrier selection depending on the final application.

Emerging insights on drug delivery by fatty acid mediated synthesis of lipophilic prodrugs as novel nanomedicines

Many drug molecules that are currently in the market suffer from short half-life, poor absorption, low specificity, rapid degradation, and resistance development. The design and development of lipophilic prodrugs can provide numerous benefits to overcome these challenges. Fatty acids (FAs), which are lipophilic biomolecules constituted of essential components of the living cells, carry out many necessary functions required for the development of efficient prodrugs. Chemical conjugation of FAs to drug molecules may change their pharmacodynamics/pharmacokinetics in vivo and even their toxicity profile. Well-designed FA-based prodrugs can also present other benefits, such as improved oral bioavailability, promoted tumor targeting efficiency, controlled drug release, and enhanced cellular penetration, leading to improved therapeutic efficacy. In this review, we discuss diverse drug molecules conjugated to various unsaturated FAs. Furthermore, various drug-FA conjugates loaded into various nanostructure delivery systems, including liposomes, solid lipid nanoparticles, emulsions, nano-assemblies, micelles, and polymeric nanoparticles, are reviewed. The present review aims to inspire readers to explore new avenues in prodrug design based on the various FAs with or without nanostructured delivery systems.

Novel thymoquinone lipidic core nanocapsules with anisamide-polymethacrylate shell for colon cancer cells overexpressing sigma receptors

The biggest challenge in colorectal cancer therapy is to avoid intestinal drug absorption before reaching the colon, while focusing on tumor specific delivery with high local concentration and minimal toxicity. In our work, thymoquinone (TQ)-loaded polymeric nanocapsules were prepared using the nanoprecipitation technique using Eudragit S100 as polymeric shell. Conjugation of anisamide as a targeting ligand for sigma receptors overexpressed by colon cancer cells to Eudragit S100 was carried out via carbodiimide coupling reaction, and was confirmed by thin layer chromatography and ¹H-NMR. TQ nanocapsules were characterized for particle size, surface morphology, zeta potential, entrapment efficiency % (EE%), in vitro drug release and physical stability. A cytotoxicity study on three colon cancer cell lines (HT-29, HCT-116, Caco-2) was performed. Results revealed that the polymeric nanocapsules were successfully prepared, and the in vitro characterization showed a suitable size, zeta potential, EE% and physical stability. TQ exhibited a delayed release pattern from the nanocapsules in vitro. Anisamide-targeted TQ nanocapsules showed higher cytotoxicity against HT-29 cells overexpressing sigma receptors compared to their non-targeted counterparts and free TQ after incubation for 48 h, hence delineating anisamide as a promising ligand for active colon cancer targeting.

Synthesis of HA-SS-MP: A Prodrug With High Specificity for Cancer Cells

Thiolated hyaluronic acid was synthesized, and a quantification method was established to determine the content of the thiol group. Three thiol compounds, 2-nitro-5-mercapto-benzoic acid (TNB), 2- mercaptonicotinic acid (2-MNA), and mercaptopyridine (MPD), were tested for their efficiency in forming adducts with hyaluronic acid (HA) through disulfide bonds. Our results showed that MPD exhibited the highest disulfide exchange efficiency when the reaction was conducted at the optimal pH value. The synthesized hyaluronic acid-SS-mercaptopurine (HA-SS-MP) was characterized by1H-nuclear magnetic resonance spectroscopy. The HA-SS-MP micelle showed a particle size of 264.4 nm in aqueous solution. An in vitro release experiment demonstrated that the releasing rate of 6-MP from HA-SS-MP in the release medium containing glutathione (GSH) was much higher than that in the release medium without GSH. Cell uptake experiments demonstrated the CD44 targeting of hyaluronic acid. Cytotoxicity tests in mouse melanoma cells (B16F10) showed that HA-SS-MP can kill melanoma cells effectively and with lower cytotoxicity, compared with the active ingredient, 6-MP.

Dual Receptor-Targeted and Redox-Sensitive Polymeric Micelles Self-Assembled from a Folic Acid-Hyaluronic Acid-SS-Vitamin E Succinate Polymer for Precise Cancer Therapy

Purpose

Poor site-specific delivery and insufficient intracellular drug release in tumors are inherent disadvantages to successful chemotherapy. In this study, an extraordinary polymeric micelle nanoplatform was designed for the efficient delivery of paclitaxel (PTX) by combining dual receptor-mediated active targeting and stimuli response to intracellular reduction potential.

Methods

The dual-targeted redox-sensitive polymer, folic acid-hyaluronic acid-SS-vitamin E succinate (FHSV), was synthesized via an amidation reaction and characterized by ¹H-NMR. Then, PTX-loaded FHSV micelles (PTX/FHSV) were prepared by a dialysis method. The physiochemical properties of the micelles were explored. Moreover, in vitro cytological experiments and in vivo animal studies were carried out to evaluate the antitumor efficacy of polymeric micelles.

Results

The PTX/FHSV micelles exhibited a uniform, near-spherical morphology (148.8 ± 1.4 nm) and a high drug loading capacity (11.28% ± 0.25). Triggered by the high concentration of glutathione, PTX/FHSV micelles could quickly release their loaded drug into the release medium. The in vitro cytological evaluations showed that, compared with Taxol or single receptor-targeted micelles, FHSV micelles yielded higher cellular uptake by the dual receptor-mediated endocytosis pathway, thus leading to significantly superior cytotoxicity and apoptosis in tumor cells but less cytotoxicity in normal cells. More importantly, in the in vivo antitumor experiments, PTX/FHSV micelles exhibited enhanced tumor accumulation and produced remarkable tumor growth inhibition with minimal systemic toxicity.

Conclusion

Our results suggest that this well-designed FHSV polymer has promising potential for use as a vehicle of chemotherapeutic drugs for precise cancer therapy.

Hyaluronic Acid-Based Theranostic Nanomedicines for Targeted Cancer Therapy

Hyaluronic acid (HA) is a natural mucopolysaccharide and has many useful advantages, including biocompatibility, non-immunogenicity, chemical versatility, non-toxicity, biodegradability, and high hydrophilicity. Numerous tumor cells overexpress several receptors that have a high binding affinity for HA, while these receptors are poorly expressed in normal body cells. HA-based drug delivery carriers can offer improved solubility and stability of anticancer drugs in biological environments and allow for the targeting of cancer treatments. Based on these benefits, HA has been widely investigated as a promising material for developing the advanced clinical cancer therapies in various formulations, including nanoparticles, micelles, liposomes, and hydrogels, combined with other materials. We describe various approaches and findings showing the feasibility of improvement in theragnosis probes through the application of HA.

Supercritical carbon dioxide techniques for processing microbial exopolysaccharides used in biomedical applications

Microbial exopolysaccharides are polymers that show a great potential for biomedical applications, such as tissue engineering applications and drug delivery, due to their biocompatibility, biodegradability and their gelling properties. These polysaccharides are obtained from a microorganism culture with a relatively straightforward downstream process thanks to their extracellular character, and can be processed to obtain aerogels, fibers and micro- or nano-particles with conventional techniques. However, these techniques present several disadvantages in that they involve time-consuming processes and the use of toxic solvents. Supercritical carbon dioxide techniques can overcome these drawbacks, but their use for processing microbial exopolysaccharides is not extended in the scientific community. This review describes the most frequently used exopolysaccharides in biomedical applications and how they can be obtained, as well as the different supercritical carbon dioxide techniques that can be used for processing them and their challenges. Specifically, high pressure shows a great potential to process and sterilize exopolysaccharide biomaterials for biomedical applications (e.g. tissue engineering or drug delivery systems) in spite of the disadvantage concerning the hydrophilicity of this type of polymers.

Supramolecular functionalization of carbon nano-onions with hyaluronic acid-phospholipid conjugates for selective targeting of cancer cells

Carbon nano-onions (CNOs) are promising materials for biomedical applications due to their low cytotoxicity and excellent biocompatibility. Supramolecular functionalization with biocompatible polymers is an effective strategy to develop engineered drug carriers for targeted delivery applications. In this study, we report the use of a hyaluronic acid-phospholipid (HA-DMPE) conjugate to target CD44 overexpressing cancer cells, while enhancing solubility of the nanoconstruct. Non-covalently functionalized CNOs with HA-DMPE show excellent in vitro cell viability in human breast carcinoma cells overexpressing CD44 and are uptaken to a greater extent compared to human ovarian carcinoma cells with an undetectable amount of CD44. In addition, they possess high in vivo biocompatibility in zebrafish (Danio Rerio) during the different stages of development and they prevalently localize in the digestive tract of the zebrafish larvae.

Dually Active Targeting Nanomedicines Based on a Direct Conjugate of Two Purely Natural Ligands for Potent Chemotherapy of Ovarian Tumors

Actively targeted nanomedicines have promised to revolutionize cancer treatment; however, their clinical translation has been limited by either low targetability, use of unsafe materials, or tedious fabrication. Here, we developed CD44 and folate receptor (FR) dually targeted nanoparticulate doxorubicin (HA/FA-NP-DOX) based on a direct conjugate of two purely natural ligands, hyaluronic acid and folic acid (FA), for safe, highly specific, and potent treatment of ovarian tumors in vivo. HA/FA-NP-DOX had a small size and high DOX loading, wherein the particle size decreased from 115, 93, to 89 nm with increasing degree of substitution of FA from 6.4, 8.5, to 11.1, while increased from 80, 93, to 103 nm with increasing DOX loading from 15.0, 23.1, to 31.4 wt %. Interestingly, HA/FA-NP-DOX exhibited excellent lyophilization redispersibility and long-term storage stability with negligible drug leakage while it released 91% of DOX in 48 h at pH 5.0. Cellular studies corroborated that HA/FA-NP-DOX possessed high selectivity to both CD44 and FR, resulting in strong killing of CD44- and FR-positive SKOV-3 ovarian cancer cells while low toxicity against CD44- and FR-negative L929 fibroblast cells. In vivo studies revealed a long elimination half-life of 5.6 h, an elevated tumor accumulation of 12.0% ID/g, and an effective inhibition of the SKOV-3 ovarian tumor for HA/FA-NP-DOX, leading to significant survival benefits over free DOX·HCl and phosphate-buffered saline controls. These dually targeted nanomedicines are simple and safe, providing a potentially translatable treatment for CD44- and FR-positive malignancies.

Biodegradable Polymers for Gene Delivery

The cellular transport process of DNA is hampered by cell membrane barriers, and hence, a delivery vehicle is essential for realizing the potential benefits of gene therapy to combat a variety of genetic diseases. Virus-based vehicles are effective, although immunogenicity, toxicity and cancer formation are among the major limitations of this approach. Cationic polymers, such as polyethyleneimine are capable of condensing DNA to nanoparticles and facilitate gene delivery. Lack of biodegradation of polymeric gene delivery vehicles poses significant toxicity because of the accumulation of polymers in the tissue. Many attempts have been made to develop biodegradable polymers for gene delivery by modifying existing polymers and/or using natural biodegradable polymers. This review summarizes mechanistic aspects of gene delivery and the development of biodegradable polymers for gene delivery.

Insights into Active Targeting of Nanoparticles in Drug Delivery: Advances in Clinical Studies and Design Considerations for Cancer Nanomedicine

Nanomedicine is a promising strategy for improving clinical outcomes for cancer therapies, by improving drug efficacy through enhanced delivery to disease sites. It is of importance for ultimate clinical success to consider the contributing factors to achieving this goal, such as size, chemistry, and functionality of nanoparticle delivery systems, and how these parameters influence tumor localization and uptake. This Topical Review will first discuss the evolution and progress of nanoparticles for cancer drug delivery and the current challenges that remain to be addressed. Strategies for overcoming the limitations of passive targeting through active targeting approaches, and the current state of such nanomedicines in the clinic will be highlighted. Finally, novel approaches toward the design of active targeted nanoparticles building on our growing understanding of nanobio interactions are considered, in order to shed light on future design considerations for accelerating clinical translation of nanomedicines.

Optimization of the Conditions for Plasmid DNA Delivery and Transfection with Self-Assembled Hyaluronic Acid-Based Nanoparticles

Polymeric systems have been extensively studied as polyelectrolyte complexes to enhance the cellular delivery and transfection efficiency of genetic materials, such as plasmid DNA (pDNA). Here, self-assembled nanoparticles were formulated by complexation of hyaluronic acid (HA)-conjugated poly(ethylene glycol) (HA-PEG) and poly(ethylenimine) (HA-PEI), respectively, with pDNA creating relatively small, stable, and multifunctional nanoparticle complex formulations with high transfection efficiency. This formulation strategy offers high gene expression efficiency and negligible cytotoxicity in HeLa and A549 human lung cancer cell lines. To develop the ideal formulation, in vitro transfection efficiency was studied for three different nanoparticle formulations (HA-PEI/HA-PEG, HA-PEI, and HA-PEG) with different concentrations. The combination of the three polymers (HA, PEG, and PEI) was significant for the formulation to achieve the maximum gene expression results. The nanoparticles were found to be stable for up to a week at 4 °C conditions. Overall, these HA-based nanoparticles showed promising aspects that can be utilized in the designing of gene delivery vectors for cancer therapy.

The Microfluidic Technique and the Manufacturing of Polysaccharide Nanoparticles

The microfluidic technique has emerged as a promising tool to accelerate the clinical translation of nanoparticles, and its application affects several aspects, such as the production of nanoparticles and the in vitro characterization in the microenvironment, mimicking in vivo conditions. This review covers the general aspects of the microfluidic technique and its application in several fields, such as the synthesis, recovering, and samples analysis of nanoparticles, and in vitro characterization and their in vivo application. Among these, advantages in the production of polymeric nanoparticles in a well-controlled, reproducible, and high-throughput manner have been highlighted, and detailed descriptions of microfluidic devices broadly used for the synthesis of polysaccharide nanoparticles have been provided. These nanoparticulate systems have drawn attention as drug delivery vehicles over many years; nevertheless, their synthesis using the microfluidic technique is still largely unexplored. This review deals with the use of the microfluidic technique for the synthesis of polysaccharide nanoparticles; evaluating features of the most studied polysaccharide drug carriers, such as chitosan, hyaluronic acid, and alginate polymers. The critical assessment of the most recent research published in literature allows us to assume that microfluidics will play an important role in the discovery and clinical translation of nanoplatforms.

Evaluation of the Impact of Preoperative Values of Hyaluronic Acid and Type IV Collagen on the Outcome of Patients with Hepatocellular Carcinoma After Hepatectomy

BACKGROUND

Recently, some reports have revealed a relationship between post-hepatectomy prognosis in hepatocellular carcinoma (HCC) and hepatic fibrosis markers. We evaluated the relationship between these markers of hepatic fibrosis, clinicopathological findings, and prognosis.

METHODS

Three hundred and sixty patients underwent hepatectomy for HCC in the Nippon Medical School Hospital between 1993 and 2013. We divided these patients into two groups: normal serum hyaluronic acid (HA) levels and abnormal levels. We also divided patients into groups with normal serum type IV collagen levels and abnormal levels.

RESULTS

The overall survival rate and recurrence-free survival rate of the normal group were significantly higher than those of the abnormal group. In the normal hyaluronic acid group, serum albumin and prothrombin time were significantly higher than in the abnormal group, and age, hepatitis C virus antibody (HCV)-Ab positivity, Child-Pugh grade B, liver cirrhosis, indocyanine green retention rate at 15 min (ICGR15), type IV collagen level, and type IV collagen 7s level were significantly lower than those in the abnormal group. In the normal type IV collagen group, HCV-Ab positivity, liver cirrhosis, ICGR15, HA level, and type IV collagen 7s level were significantly lower than those in the abnormal group, and the serum albumin level was significantly higher than that in the abnormal group. Multivariate analysis independently revealed the significant effect of serum type IV collagen on the overall survival rate as well as the significant effect of serum HA on the recurrence-free survival rate in patients who underwent hepatectomy for HCC.

CONCLUSIONS

Preoperative examinations of serum hyaluronic acid levels and type IV collagen levels are imperative for hepatic resection for HCC because these markers are significantly associated with liver function and prognosis.

Hyaluronic Acid-Based Nanomaterials for Cancer Therapy

Hyaluronic acid (HA) is a nonsulfated glycosaminoglycan and a major component of the extracellular matrix. HA is overexpressed by numerous tumor cells, especially tumor-initiating cells. HA-based nanomaterials play in importance role in drug delivery systems. HA is used in various types of nanomaterials including micelle, polymersome, hydrogel, and inorganic nanoparticle formulations. Many experiments show that HA-based nanomaterials can serve as a platform for targeted chemotherapy, gene therapy, immunotherapy, and combination therapy with good potential for future biomedical applications in cancer treatment.

Novel targets for delaying aging: The importance of the liver and advances in drug delivery

Age-related changes in liver function have a significant impact on systemic aging and susceptibility to age-related diseases. Nutrient sensing pathways have emerged as important targets for the development of drugs that delay aging and the onset age-related diseases. This supports a central role for the hepatic regulation of metabolism in the association between nutrition and aging. Recently, a role for liver sinusoidal endothelial cells (LSECs) in the relationship between aging and metabolism has also been proposed. Age-related loss of fenestrations within LSECs impairs the transfer of substrates (such as lipoproteins and insulin) between sinusoidal blood and hepatocytes, resulting in post-prandial hyperlipidemia and insulin resistance. Targeted drug delivery methods such as nanoparticles and quantum dots will facilitate the direct delivery of drugs that regulate fenestrations in LSECs, providing an innovative approach to ameliorating age-related diseases and increasing healthspan.

Hyaluronic Acid-Decorated Chitosan Nanoparticles for CD44-Targeted Delivery of Everolimus

Bronchiolitis obliterans syndrome (BOS), caused by lung allograft-derived mesenchymal cells' abnormal proliferation and extracellular matrix deposition, is the main cause of lung allograft rejection. In this study, a mild one-step ionotropic gelation method was set up to nanoencapsulate the everolimus, a key molecule in allograft organ rejection prevention, into hyaluronic acid-decorated chitosan-based nanoparticles. Rationale was the selective delivery of everolimus into lung allograft-derived mesenchymal cells; these cells are characterized by the CD44-overexpressing feature, and hyaluronic acid has proven to be a natural selective CD44-targeting moiety. The optimal process conditions were established by a design of experiment approach (full factorial design) aiming at the control of the nanoparticle size (≤200 nm), minimizing the size polydispersity (PDI 0.171 ± 0.04), and at the negative ζ potential maximization (-30.9 mV). The everolimus was successfully loaded into hyaluronic acid-decorated chitosan-based nanoparticles (95.94 ± 13.68 μg/100 mg nanoparticles) and in vitro released in 24 h. The hyaluronic acid decoration on the nanoparticles provided targetability to CD44-overexpressing mesenchymal cells isolated from bronchoalveolar lavage of BOS-affected patients. The mesenchymal cells' growth tests along with the nanoparticles uptake studies, at 37 °C and 4 °C, respectively, demonstrated a clear improvement of everolimus inhibitory activity when it is encapsulated in hyaluronic acid-decorated chitosan-based nanoparticles, ascribable to their active uptake mechanism.

Reduction-sensitive CD44 receptor-targeted hyaluronic acid derivative micelles for doxorubicin delivery

Introduction

A reduction-sensitive CD44-positive tumor-targetable drug delivery system for doxorubicin (DOX) delivery was developed based on hyaluronic acid (HA)-grafted polymers.

Materials and methods

HA was conjugated with folic acid (FA) via a reduction-sensitive disulfide linkage to form an amphiphilic polymer (HA-ss-FA). The chemical structure of HA-ss-FA was analyzed by ultraviolet spectroscopy, Fourier transform infrared spectroscopy, and ¹H nuclear magnetic resonance (NMR) spectroscopy. The molecular weight of HA-ss-FA was determined by high-performance gel permeation chromatography. Blank HA-ss-FA micelles and DOX-loaded micelles were prepared and characterized. The reduction responsibility, cellular uptake, and in vivo biodistribution of HA-ss-FA micelles were investigated.

Results

DOX-loaded micelles were of high encapsulation efficiency (88.09%), high drug-loading content (22.70%), appropriate mean diameter (100-120 nm), narrow size distribution, and negative zeta potential (-6.7 to -31.5 mV). The DOX release from the micelles was significantly enhanced in reduction environment compared to normal environment. The result of in vitro cytotoxicity assay indicated that the blank micelles were of low toxicity and good biocompatibility and the cell viabilities were >100% with the concentration of HA-ss-FA from 18.75 to 600.00 μg/mL. Cellular uptake and in vivo biodistribution studies showed that DOX-loaded micelles were tumor-targetable and could significantly enhance cellular uptake by CD44 receptor-mediated endocytosis, and the cellular uptake of DOX in CD44-positve A549 cells was 1.6-fold more than that in CD44-negative L02 cells. In vivo biodistribution of HA-ss-FA micelles showed that micelles were of good in vivo tumor targetability and the fluorescence of indocyanine green (ICG)-loaded micelles was 4- to 6.6-fold stronger than free ICG within 6 h in HCCLM3 tumor-bearing nude mice.

Conclusion

HA-ss-FA is a promising nanocarrier with excellent biocompatibility, tumor targetability, and controlled drug release capability for delivery of chemotherapy drugs in cancer therapy.

Nanoparticles and Controlled Delivery for Bioactive Compounds: Outlining Challenges for New "Smart-Foods" for Health

Nanotechnology is a field of research that has been stressed as a very valuable approach for the prevention and treatment of different human health disorders. This has been stressed as a delivery system for the therapeutic fight against an array of pathophysiological situations. Actually, industry has applied this technology in the search for new oral delivery alternatives obtained upon the modification of the solubility properties of bioactive compounds. Significant works have been made in the last years for testing the input that nanomaterials and nanoparticles provide for an array of pathophysiological situations. In this frame, this review addresses general questions concerning the extent to which nanoparticles offer alternatives that improve therapeutic value, while avoid toxicity, by releasing bioactive compounds specifically to target tissues affected by specific chemical and pathophysiological settings. In this regard, to date, the contribution of nanoparticles to protect encapsulated bioactive compounds from degradation as a result of gastrointestinal digestion and cellular metabolism, to enable their release in a controlled manner, enhancing biodistribution of bioactive compounds, and to allow them to target those tissues affected by biological disturbances has been demonstrated.

Molecular Insights of Hyaluronic Acid as Potential Source of Polymer-Drug Conjugate in the Target-Mediated Treatment of Cancer

The naturally occurring polysaccharide hyaluronic acid (HA) is a major component of the extracellular matrix and is found over expressed in many cancer cells. Hyaluronic acid is reported to be a potential carrier for drug delivery with the dual advantage of accumulation at the tumor site and receptor-mediated uptake. The use of drugs conjugated with macromolecules was shown to improve the drug pharmacokinetic profile. The various biological potentials such as biodegradability, biocompatibility, non-toxicity, hydrophilicity and non-immunogenicity, together with the availability of various chemical groups that allow the conjugation of drugs, put forward HA as a potential choice for the development of drug conjugates. In this context, the present study is focused to provide, through docking studies, insights on the activity of cancer drugs such as methotrexate, 3′,5′-dichloromethotrexate and ornithine-methotrexate and their activity against the receptor caspase-1, which is a well-established drug target in the treatment of cancer. The docking study envisages that the usage of methotrexate properly conjugated to the natural polysaccharide HA might serve as a potential drug to effectively treat some cancer diseases.

Pursuing Intracellular Pathogens with Hyaluronan. From a 'Pro-Infection' Polymer to a Biomaterial for 'Trojan Horse' Systems

Hyaluronan (HA) is among the most important bioactive polymers in mammals, playing a key role in a number of biological functions. In the last decades, it has been increasingly studied as a biomaterial for drug delivery systems, thanks to its physico-chemical features and ability to target and enter certain cells. The most important receptor of HA is ‘Cluster of Differentiation 44’ (CD44), a cell surface glycoprotein over-expressed by a number of cancers and heavily involved in HA endocytosis. Moreover, CD44 is highly expressed by keratinocytes, activated macrophages and fibroblasts, all of which can act as ‘reservoirs’ for intracellular pathogens. Interestingly, both CD44 and HA appear to play a key role for the invasion and persistence of such microorganisms within the cells. As such, HA is increasingly recognised as a potential target for nano-carriers development, to pursuit and target intracellular pathogens, acting as a ‘Trojan Horse’. This review describes the biological relationship between HA, CD44 and the entry and survival of a number of pathogens within the cells and the subsequent development of HA-based nano-carriers for enhancing the intracellular activity of antimicrobials.

Enhanced delivery of doxorubicin to the liver through self-assembled nanoparticles formed via conjugation of glycyrrhetinic acid to the hydroxyl group of hyaluronic acid

Liver-targeted nanoparticles is highly desired for better therapy of liver cancer. In this study, enhanced delivery of doxorubicin (DOX) to the liver cells through self-assembled nanoparticles formed via conjugation of glycyrrhetinic acid (GA) to the hydroxyl group of hyaluronic acid (HA) was investigated. The DOX loaded hyaluronic acid-glycyrrhetinic acid succinate (HSG) conjugates based nanoparticles (HSG/DOX nanoparticles) were sub-spherical in shape with particle size in the range of 180-280 nm, the drug loading was drug-to-carrier ratio and GA graft ratio dependent. In vitro release study suggested that the release of DOX from HSG nanoparticles was sustained and the release rate was pH and GA graft ratio dependent. MTT assay indicated the HSG/DOX nanoparticles presented a GA-dependent cytotoxicity to HepG2 cells. Pharmacokinetics study demonstrated the HSG/DOX nanoparticles could prolong blood circulation time of DOX and had a higher AUC value than that of DOX solution. Furthermore, tissue distribution study revealed the HSG/DOX nanoparticles significantly increased the accumulation of DOX in the liver and meanwhile decreased the cardiotoxicity and nephrotoxicity of DOX. Moreover, the liver targeting enhancing capacity was HSG conjugate structure dependent. The accumulation of HSG-20/DOX, HSG-12/DOX, and HSG-6/DOX nanoparticles in the liver was 4.0-, 3.1-, and 2.6-fold higher than that of DOX solution. In vivo imaging analysis further demonstrated HSG nanoparticles not only had better liver targeting effect, but also presented superior tumor targeting efficiency, and the tumor targeting capacity was also GA-dependent. These results indicated that HSG conjugates prepared via modifying the hydroxyl groups of HA have promising potential as a liver-targeting nanocarrier for the delivery of hydrophobic anti-tumor drugs.

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.