CD44-Targeted Facile Enzymatic Activatable Chitosan Nanoparticles for Efficient Antitumor Therapy and Reversal of Multidrug Resistance

Exploring the promising role of chitosan delivery systems in breast cancer treatment: A comprehensive review

Breast cancer presents a significant global health challenge, driving the development of novel treatment strategies for therapeutic interventions. Nanotechnology has emerged as a promising avenue for addressing this challenge, with Chitosan (CS) nanoparticles receiving prominence due to their unique characteristics and multitude of potential applications. This review provides a comprehensive overview of the role of Chitosan nanoparticles in breast cancer therapy. The review begins by emphasizing the prevalence and importance of breast cancer as a major health issue, underscoring the necessity for effective treatments. It then delves into the application of Chitosan nanoparticles in breast cancer therapy. One key aspect discussed is their role as carriers for anticancer drugs, enabling targeted delivery and improved cellular uptake. Furthermore, the review explores modified Chitosan nanoparticles and strategies for enhancing their efficacy and specificity in breast cancer treatment. It also examines Chitosan conjugates and hybrids, which offer innovative approaches for combination therapy. Additionally, metal and magnetic Chitosan nanoparticles are discussed spanning their capacity to assist in imaging, hyperthermia, as well as targeted drug delivery. In conclusion, the review summarizes the current research landscape regarding Chitosan nanoparticles for breast cancer therapy and offers insights into future directions. Overall, the review highlights the versatility, potential benefits, and future prospects of Chitosan nanoparticles in combating breast cancer.

Stimuli-Responsive Prodrug Chemistries for Cancer Therapy

Prodrugs are pharmacologically inactive, chemically modified derivatives of active drugs, which, following in vivo administration, are converted to the parent drugs through chemical or enzymatic cleavage. The prodrug approach holds tremendous potential to create the enhanced version of an existing pharmacological agent and leverage those improvements to augment the drug molecules' bioavailability, targeting ability, therapeutic efficacy, safety, and marketability. Especially in cancer therapy, prodrug application has received substantial attention. A prodrug can effectively broaden the therapeutic window of its parent drug by enhancing its release at targeted tumor sites while reducing its access to healthy cells. The spatiotemporally controlled release can be achieved by manipulating the chemical, physical, or biological stimuli present at the targeted tumor site. The critical strategy comprises drug-carrier linkages that respond to physiological or biochemical stimuli in the tumor milieu to yield the active drug form. This review will focus on the recent advancements in the development of various fluorophore-drug conjugates that are widely used for real-time monitoring of drug delivery. The use of different stimuli-cleavable linkers and the mechanisms of linker cleavage will be discussed. Finally, the review will conclude with a critical discussion of the prospects and challenges that might impede the future development of such prodrugs.

Cancer Cell-Specific Fluorescent Prodrug Delivery Platforms

Targeting cancer cells with high specificity is one of the most essential yet challenging goals of tumor therapy. Because different surface receptors, transporters, and integrins are overexpressed specifically on tumor cells, using these tumor cell-specific properties to improve drug targeting efficacy holds particular promise. Targeted fluorescent prodrugs not only improve intracellular accumulation and bioavailability but also report their own localization and activation through real-time changes in fluorescence. In this review, efforts are highlighted to develop innovative targeted fluorescent prodrugs that efficiently accumulate in tumor cells in different organs, including lung cancer, liver cancer, cervical cancer, breast cancer, glioma, and colorectal cancer. The latest progress and advances in chemical design and synthetic considerations in fluorescence prodrug conjugates and how their therapeutic efficacy and fluorescence can be activated by tumor-specific stimuli are reviewed. Additionally, novel perspectives are provided on strategies behind engineered nanoparticle platforms self-assembled from targeted fluorescence prodrugs, and how fluorescence readouts can be used to monitor the position and action of the nanoparticle-mediated delivery of therapeutic agents in preclinical models. Finally, future opportunities for fluorescent prodrug-based strategies and solutions to the challenges of accelerating clinical translation for the treatment of organ-specific tumors are proposed.

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].

Recent advances in anti-multidrug resistance for nano-drug delivery system

Chemotherapy for tumors occasionally results in drug resistance, which is the major reason for the treatment failure. Higher drug doses could improve the therapeutic effect, but higher toxicity limits the further treatment. For overcoming drug resistance, functional nano-drug delivery system (NDDS) has been explored to sensitize the anticancer drugs and decrease its side effects, which are applied in combating multidrug resistance (MDR) via a variety of mechanisms including bypassing drug efflux, controlling drug release, and disturbing metabolism. This review starts with a brief report on the major MDR causes. Furthermore, we searched the papers from NDDS and introduced the recent advances in sensitizing the chemotherapeutic drugs against MDR tumors. Finally, we concluded that the NDDS was based on several mechanisms, and we looked forward to the future in this field.

Taxanes prodrug-based nanomedicines for cancer therapy

Malignant tumor remains a huge threat to human health and chemotherapy still occupies an important place in clinical tumor treatment. As a kind of potent antimitotic agent, taxanes act as the first-line broad-spectrum cancer drug in clinical use. However, disadvantages such as prominent hydrophobicity, severe off-target toxicity or multidrug resistance lead to unsatisfactory therapeutic effects, which restricts its wider usage. The efficient delivery of taxanes is still quite a challenge despite the rapid developments in biomaterials and nanotechnology. Great progress has been made in prodrug-based nanomedicines (PNS) for cancer therapy due to their outstanding advantages such as high drug loading efficiency, low carrier induced immunogenicity, tumor stimuli-responsive drug release, combinational therapy and so on. Based on the numerous developments in this filed, this review summarized latest updates of taxanes prodrugs-based nanomedicines (TPNS), focusing on polymer-drug conjugate-based nanoformulations, small molecular prodrug-based self-assembled nanoparticles and prodrug-encapsulated nanosystems. In addition, the new trends of tumor stimuli-responsive TPNS were also discussed. Moreover, the future challenges of TPNS for clinical translation were highlighted. We here expect this review will inspire researchers to explore more practical taxanes prodrug-based nano-delivery systems for clinical use.

Comparison of National Growth Standards for Turkish Infants and Children with World Health Organization Growth Standards

OBJECTIVE

Using World Health Organization (WHO) standards in pediatric practice is still controversial in many countries. It is suggested that national growth charts best reflect the genetic and ethnic characteristics of a population. The aim of this study was to compare length/height, body weight, and body mass index (BMI) in healthy Turkish children of ages 0 to 18 with those proposed by WHO as the international growth standards.

METHODS

The data of Turkish children were collected from infant/child population aged 0-5 years (2391 boys, 2102 girls) and children of ages between 6-18 years (1100 boys, 1020 girls). For comparison, the 50^th, 3^rd, and 97^th percentile curves for length/height, weight, and BMI in Turkish children were plotted together with respective WHO data.

RESULTS

Heights were essentially similar in the Turkish and WHO data at ages between 3-10 years. Turkish children were markedly taller compared to the WHO standards after the age of 10 years. Evaluation of the 3rd percentile data revealed that Turkish boys were shorter than the WHO subjects in the first 2 years of life. From 6 months of age, Turkish children showed higher weight for age values in the 3^rd, 50^th, and 97^th percentiles. In all age groups between 6 months and 3 years, and in between 6-18 years of age, Z-score values, as well as the 50^th, 15^th, 85^th, and 95^th percentile values were higher in Turkish children. The differences were particularly noteworthy at ages 1-2 years and in the pubertal years.

CONCLUSION

WHO growth standards do not reflect the growth of Turkish children and may substantially alter the prevalence of short stature and underweight in Turkish children in the 0-5 years age group. When assessing the nutritional and growth status of children, national growth standards may be more appropriate.

Two-Pronged Anti-Tumor Therapy by a New Polymer-Paclitaxel Conjugate Micelle with an Anti-Multidrug Resistance Effect

Introduction

Cancerous tumors are still a major disease that threatens human life, with tumor multidrug resistance (MDR) being one of the main reasons for the failure of chemotherapy. Thus, reversing tumor MDR has become a research focus of medical scientists.

Methods

Here, a reduction-sensitive polymer prodrug micelle, mPEG-DCA-SS-PTX (PDSP), was manufactured with a new polymer inhibitor of drug resistance as a carrier to overcome MDR and improve the anti-tumor effect of PTX.

Results

The PDSP micelles display good stability, double-responsive drug release, and excellent biocompatibility. The PDSP micelles reduced the cytotoxicity of PTX to normal HL-7702 cells and enhanced that to SMMC-7721 and MCF-7 cells in vitro. Improved sensitivity of A549/ADR to PDSP was also observed in vitro. Furthermore, in vivo experiments show reduced systemic toxicity and enhanced therapeutic efficacy of PTX to H22 subcutaneous tumor-bearing mice.

Conclusion

This work proves that the reduction-sensitive polymer prodrug micelles carried by the new polymer inhibitor can be used as an alternative delivery system to target tumors and reverse MDR for paclitaxel and other tumor-resistant drugs.

Chitosan Nanoparticle-Based System: A New Insight into the Promising Controlled Release System for Lung Cancer Treatment

Lung cancer has been recognized as one of the most often diagnosed and perhaps most lethal cancer diseases worldwide. Conventional chemotherapy for lung cancer-related diseases has bumped into various limitations and challenges, including non-targeted drug delivery, short drug retention period, low therapeutic efficacy, and multidrug resistance (MDR). Chitosan (CS), a natural polymer derived from deacetylation of chitin, and comprised of arbitrarily distributed β-(1-4)-linked d-glucosamine (deacetylated unit) and N-acetyl-d-glucosamine (acetylated unit) that exhibits magnificent characteristics, including being mucoadhesive, biodegradable, and biocompatible, has emerged as an essential element for the development of a nano-particulate delivery vehicle. Additionally, the flexibility of CS structure due to the free protonable amino groups in the CS backbone has made it easy for the modification and functionalization of CS to be developed into a nanoparticle system with high adaptability in lung cancer treatment. In this review, the current state of chitosan nanoparticle (CNP) systems, including the advantages, challenges, and opportunities, will be discussed, followed by drug release mechanisms and mathematical kinetic models. Subsequently, various modification routes of CNP for improved and enhanced therapeutic efficacy, as well as other restrictions of conventional drug administration for lung cancer treatment, are covered.

Cascade-responsive nano-assembly for efficient photothermal-chemo synergistic inhibition of tumor metastasis by targeting cancer stem cells

Metastasis has been widely recognized as the most lethal threats for cancer patients. Due to their special genetic and environmental context, cancer stem cells (CSCs) which are resistant to most cytotoxic drugs and radiation, are considered as the dominant culprit for metastasis. Thus, the efficient targeting and thorough elimination of CSCs are significantly urgent for the enhancement of therapeutic efficacy. Herein, we developed a facile and smart photothermal-chemo therapeutic nano-assembly system, of which the surface was modified by a sheddable PEG shell and acid-activatable pro-penetration peptide, to surmount the physiological barriers in targeting CSCs. A highly-efficient diradical-featured croconium-based photothermal agent and a natural cytotoxic heat shock protein (HSP) inhibitor were co-loaded in redox-sensitive chitosan matrices to realize the synergistic photothermal-chemo therapy. Within solid tumors, the PEG shell that prevents the nano-assembly from mononuclear phagocytic clearance could rapidly leave to expose the positively charged chitosan, and the detached iRGD could further actuate the tumor penetration of chitosan nanoparticles, and allow the CSCs targeting by selective recognition of CD44 protein. Owing to the HSP inhibition and chemo-sensitization, both the CSCs and non-CSCs could be thoroughly eliminated by the designed nano-assembly, largely inhibiting the tumor growth and metastasis. This work provides a potential strategy for CSCs-targeting drug delivery to solve the CSCs-related metastasis.

pH-sensitive doxorubicin-tocopherol succinate prodrug encapsulated in docosahexaenoic acid-based nanostructured lipid carriers: An effective strategy to improve pharmacokinetics and reduce toxic effects

Side effects often limit the use of doxorubicin (DOX) in cancer treatment. We have recently developed a nanostructured lipid carrier (NLC) formulation for synergistic chemotherapy, encapsulating DOX and the anticancer adjuvants docosahexaenoic acid (DHA) and α-tocopherol succinate (TS). Hydrophobic ion-pairing with TS allowed a high DOX entrapment in the nanocarrier. In this work, we investigated the pharmacokinetics of this formulation after intravenous administration in mice. The first data obtained led us to propose synthesizing covalent DOX-TS conjugates to increase DOX retention in the NLC. We successfully conjugated DOX to TS via an amide or hydrazone bond. In vitro studies in 4T1 tumor cells indicated low cytotoxicity of the amide derivative, while the hydrazone conjugate was effective in killing cancer cells. We encapsulated the hydrazone derivative in a DHA-based nanocarrier (DOX-hyd-TS/NLC), which had reduced particle size and high drug encapsulation efficiency. The pH-sensitive hydrazone bond allowed controlled DOX release from the NLC, with increased drug release at acidic conditions. In vivo studies revealed that DOX-hyd-TS/NLC had a better pharmacokinetic profile than free DOX and attenuated the short-term cardiotoxic effects caused by DOX, such as QT prolongation and impaired left ventricular systolic function. Moreover, this formulation showed excellent therapeutic performance by reducing tumor growth in 4T1 tumor-bearing mice and decreasing DOX-induced toxicity to the heart and liver, demonstrated by hematologic, biochemical, and histologic analyses. These results indicate that DOX-hyd-TS/NLC may be a promising nanocarrier for breast cancer treatment.

Construction of Novel Nanocomposites (Cu-MOF/GOD@HA) for Chemodynamic Therapy

The emerging chemodynamic therapy (CDT) has received an extensive attention in recent years. However, the efficiency of CDT is influenced due to the limitation of H2O2 in tumor. In this study, we designed and synthesized a novel core-shell nanostructure, Cu-metal organic framework (Cu-MOF)/glucose oxidase (GOD)@hyaluronic acid (HA) (Cu-MOF/GOD@HA) for the purpose of improving CDT efficacy by increasing H2O2 concentration and cancer cell targeting. In this design, Cu-MOF act as a CDT agent and GOD carrier. Cu(II) in Cu-MOF are reduced to Cu(I) by GSH to obtain Cu(I)-MOF while GSH is depleted. The depletion of GSH reinforces the concentration of H2O2 in tumor to improve the efficiency of CDT. The resultant Cu(I)-MOF catalyze H2O2 to generate hydroxyl radicals (·OH) for CDT. GOD can catalyze glucose (Glu) to supply H2O2 for CDT enhancement. HA act as a targeting molecule to improve the targeting ability of Cu-MOF/GOD@HA to the tumor cells. In addition, after loading with GOD and coating with HA, the proportion of Cu(I) in Cu-MOF/GOD@HA is increased compared with the proportion of Cu(I) in Cu-MOF. This phenomenon may shorten the reactive time from Cu-MOF to Cu(I)-MOF. The CDT enhancement as a result of GOD and HA effects in Cu-MOF/GOD@HA was evidenced by in vitro cell and in vivo animal studies.

In situ triggering antitumor efficacy of alcohol-abuse drug disulfiram through Cu-based metal-organic framework nanoparticles

Although approved as an alcohol-abuse drug, disulfiram (DSF) exhibited potential anticancer activity when chelated with copper (Cu). However, the low level of intrinsic Cu, toxicity originated from exogenous Cu supplementation, and poor stability of DSF in vivo severely limited its application in cancer treatment. Herein, we proposed an in situ DSF antitumor efficacy triggered system, taking advantages of Cu-based metal-organic framework (MOF). In detail, DSF was encapsulated into Cu-MOF nanoparticles (NPs) during its formation, and the obtained NPs were coated with hyaluronic acid to enhance the tumor targetability and biocompatibility. Notably, DSF loaded Cu-MOF NPs maintained stability and integrity without Cu2+ leakage in blood circulation, thus showing excellent biosafety. Once accumulating at tumor site, NPs were internalized into tumor cells via receptor-mediated endocytosis and released DSF and Cu2+ simultaneously in the hyaluronidase-enriched and acidic intracellular tumor microenvironment. This profile lead to in situ chelation reaction between DSF and Cu2+, generating toxic DSF/Cu complex against tumor cells. Both in vitro and in vivo results demonstrated the programmed degradation and recombination property of Cu-based MOF NPs, which facilitated the tumor-specific chemotherapeutic effects of DSF. This system provided a promising strategy for the application of DSF in tumor therapy.

Recent advances in polymer shell oily-core nanocapsules for drug-delivery applications

Polymeric nanocapsules are vesicular drug-delivery systems composed of an inner oily reservoir surrounded by polymeric membranes. Nanocapsules have various advantages over other nanovesicular systems such as providing controlled drug release properties. We discuss the recent advances in polymeric shell oily-core nanocapsules, illustrating the different types of polymers used and their implementation. Nanocapsules can be utilized for many purposes, especially encapsulation of highly lipophilic drugs. They have been shown to have variable applications, especially in cancer therapy, due to the ability of the polymeric shell to direct the loaded drugs to their target sites, as well as their high internalization efficacy. Those productive applications guaranteed their high potential as drug-delivery systems. However, their clinical development is still in an early stage.

Biomaterials for protein delivery for complex tissue healing responses

Tissue repair requires a complex cascade of events mediated by a variety of cells, proteins, and matrix molecules; however, the healing cascade can be easily disrupted by numerous factors, resulting in impaired tissue regeneration. Recent advances in biomaterials for tissue regeneration have increased the ability to tailor the delivery of proteins and other biomolecules to injury sites to restore normal healing cascades and stimulate robust tissue repair. In this review, we discuss the evolution of the field toward creating biomaterials that precisely control protein delivery to stimulate tissue regeneration, with a focus on addressing complex and dynamic injury environments. We highlight biomaterials that leverage different mechanisms to deliver and present proteins involved in healing cascades, tissue targeting and mimicking strategies, materials that can be triggered by environmental cues, and integrated strategies that combine multiple biomaterial properties to improve protein delivery. Improvements in biomaterial design to address complex injury environments will expand our understanding of both normal and aberrant tissue repair processes and ultimately provide a better standard of patient care.

A novel GSH-triggered polymeric nanomicelles for reversing MDR and enhancing antitumor efficiency of hydroxycamptothecin

Tumor multidrug resistance (MDR) is one of the main reasons for the failure of clinical chemotherapy. Here, a bio-responsive anti-drug-resistant polymer micelle that can respond to the reductive GSH in the tumor microenvironment (TME) for delivery of HCPT was designed. A new type of polymer with anti-drug resistance and anti-tumor effect was synthesized and used to encapsulated HCPT to form reduction-sensitive micelles (PDSAH) by a thin-film dispersion method. It is demonstrated that the micelle formulation improves the anti-tumor activity and biosafety of HCPT, and also plays a significant role in reversing the drug resistance, which contributes to inhibiting the tumor growth and prolonging the survival time of H22 tumor-bearing mice. The results indicate that this nanoplatform can serve as a flexible and powerful system for delivery of other drugs that are tolerated by tumors or bacteria.

Vitamin E succinate with multiple functions: A versatile agent in nanomedicine-based cancer therapy and its delivery strategies

Vitamin E succinate (VES), a succinic acid ester of vitamin E, is one of the most effective anticancer compounds of the vitamin E family. VES can inhibit tumor growth by multiple pathways mainly involve tumor proliferation inhibition, apoptosis induction, and metastasis prevention. More importantly, the mitochondrial targeting and damaging property of VES endows it with great potential in exhibiting synergetic effect with conventional chemotherapeutic drugs and overcoming multidrug resistance (MDR). Given the lipophilicity of VES that hinders its bioavailability and therapeutic activity, nanotechnology with multiple advantages has been widely explored to deliver VES and opened up new avenues for its in vivo application. This review aims to introduce the anticancer mechanisms of VES and summarize its delivery strategies using nano-drug delivery systems. Specifically, VES-based combination therapy for synergetic anticancer effect, MDR-reversal, and oral chemotherapy improvement are highlighted. Finally, the challenges and perspectives are discussed.

Prodrug Nanomedicine Inhibits Chemotherapy-Induced Proliferative Burst by Altering the Deleterious Intercellular Communication

Chemotherapy is one of the most commonly used clinical antitumor strategies. However, the therapy-induced proliferative burst, which always accompanies drug resistance and metastasis, has become a major obstacle during treatment. Except for some endogenous cellular or genetic mechanisms and some microenvironmental selection pressures, the intercellular connections in the tumor microenvironment (TME) are also thought to be the driving force for the acquired drug resistance and proliferative burst. Even though some pathway inhibitors or cell exempting strategies could be applied to partially avoid these unwanted communications, the complexity of the TME and the limited knowledge about those unknown detrimental connections might greatly compromise the efforts. Therefore, a more broad-spectrum strategy is urgently needed to relieve the drug-induced burst proliferation during various treatments. In this article, based on the possible discrepancies in metabolic activity between cells with different growth rates, several ester-bond-based prodrugs were synthesized. After screening, 7-ethyl-10-hyodroxycamptothecin-based prodrug nanoparticles were found to efficiently overcome the paclitaxel resistance, to selectively act on the malignantly proliferated drug-resistant cells and, furthermore, to greatly diminish the proliferative effect of common cytotoxic agents by blocking the detrimental intercellular connections. With the discriminating ability against malignant proliferating cells, the as-prepared prodrug nanomedicine exhibited significant anticancer efficacy against both drug-sensitive and drug-resistant tumor models, either by itself or by combining with highly potent nonselective chemotherapeutics. This work provides a different perspective and a possible solution for the treatment of therapy-induced burst proliferation.

Tumor-Targeting Glycol Chitosan Nanoparticles for Cancer Heterogeneity

Nanomedicine is extensively employed for cancer treatment owing to its unique advantages over conventional drugs and imaging agents. This increased attention to nanomedicine, however, has not fully translated into clinical utilization and patient benefits due to issues associated with reticuloendothelial system clearance, tumor heterogeneity, and complexity of the tumor microenvironment. To address these challenges, efforts are being made to modify the design of nanomedicines, including optimization of their physiochemical properties, active targeting, and response to stimuli, but these studies are often performed independently. Combining favorable nanomedicine designs from individual studies may improve therapeutic outcomes, but, this is difficult to achieve as the effects of different designs are interconnected and often conflicting. Glycol chitosan nanoparticles (CNPs) are shown to accumulate in tumors, suggesting that this type of nanoparticle may constitute a good basis for the additional modification of nanoparticles. Here, multifunctional glycol CNPs designed to overcome multiple obstacles to their use are described and key factors influencing in vivo targeted delivery, targeting strategies, and interesting stimulus-responsive designs for improving cancer nanomedicine are discussed.

Pd@Pt-GOx/HA as a Novel Enzymatic Cascade Nanoreactor for High-Efficiency Starving-Enhanced Chemodynamic Cancer Therapy

Glucose oxidase (GOx)-mediated starvation therapy has demonstrated good application prospect in cancer treatment. However, the glucose- and oxygen-depletion starvation therapy still suffers from some limitations like low therapeutic efficiency and potential side effects to normal tissues. To overcome these disadvantages, herein a novel enzymatic cascade nanoreactor (Pd@Pt-GOx/hyaluronic acid (HA)) with controllable enzymatic activities was developed for high-efficiency starving-enhanced chemodynamic cancer therapy. The Pd@Pt-GOx/HA was fabricated by covalent conjugation of GOx onto Pd@Pt nanosheets (NSs), followed by linkage with hyaluronic acid (HA). The modification of HA on Pd@Pt-GOx could block the GOx activity, catalase (CAT)-like and peroxidase (POD)-like activities of Pd@Pt, reduce the cytotoxicity to normal cells and organs, and effectively target CD44-overexpressed tumors by active targeting and passive enhanced permeability and retention (EPR) effect. After endocytosis by tumor cells, the intracellular hyaluronidase (Hyase) could decompose the outer HA and expose Pd@Pt-GOx for the enzymatic cascade reaction. The GOx on the Pd@Pt-GOx could catalyze the oxidation of intratumoral glucose by O₂ for cancer starvation therapy, while the O₂ produced from the decomposition of endogenous H₂O₂ by the Pd@Pt with the CAT-like activity could accelerate the O₂-dependent depletion of glucose by GOx. Meanwhile, the upregulated acidity and H₂O₂ content in the tumor region generated by GOx catalytic oxidation of glucose dramatically facilitated the pH-responsive POD-like activity of the Pd@Pt nanozyme, which then catalyzed degradation of the H₂O₂ to generate abundant highly toxic ^•OH, thereby realizing nanozyme-mediated starving-enhanced chemodynamic cancer therapy. In vitro and in vivo results indicated that the controllable, self-activated enzymatic cascade nanoreactors exerted highly efficient anticancer effects with negligible biotoxicity.

Exosome-like Nanoparticles: A New Type of Nanocarrier

Nanoparticles are one of the most commonly used systems for imaging or therapeutic drug delivery. Exosomes are nanovesicular carriers that transport cargo for intercellular communication. These nanovesicles are linked to the pathology of some major diseases, in some cases with a central role in their progression. The use of these carriers to transport therapeutic drugs is a recent and promising approach to treat diseases such as cancer and Alzheimer disease. The physiological production of these structures is limited impairing its collection and subsequent purification. These drawbacks inspired the search for mimetic alternatives. The collection of exosome-like nanoparticles from plants can be a good alternative, since they are easier to extract and do not have the drawbacks of those produced in animal cells. Both natural and synthetic exosome-like nanoparticles, produced from serial extrusion of cells or by bottom up synthesis, are currently some of the most promising, biocompatible, high efficiency systems for drug delivery.

RGD functionalized chitosan nanoparticle mediated targeted delivery of raloxifene selectively suppresses angiogenesis and tumor growth in breast cancer

Acidic pH is a crucial intrinsic property of the microenvironment of most solid tumors. Hence, the use of pH sensitive tumor targeting nanoparticles is an attractive approach to enhance the therapeutic efficacy of anti-cancer agents in solid tumors. Chitosan nanoparticles (CHNPs) have been widely explored in the area of cancer drug delivery; nevertheless their true potential as a pH responsive targeted drug delivery vehicle in cancer therapy has not been deciphered yet as most of the research is limited to pH dependent stability and drug release. In the present study, we investigate the direct effect of pH in synergy with RGD peptide based targeting on the therapeutic efficacy of chitosan nanoparticles (RGD-CHNPs) in breast cancer. Furthermore, for the first time we performed a comprehensive study showing the anti-tumor, anti-migratory and anti-angiogenic effect of raloxifene (Rlx) loaded CHNPs in breast cancer. We prepared stable formulations of raloxifene encapsulated CHNPs and RGD-CHNPs by the nontoxic ionic gelation method. pH dependent studies revealed that NPs possess higher stability and zeta potential along with enhanced cellular uptake at acidic pH (as present in solid tumors) compared to physiological pH. Furthermore, RGD conjugation enhanced the in vitro cellular uptake of CHNPs in α_vβ₃ integrin expressing breast cancer cells and induced higher cellular apoptosis in breast cancer cells which was further augmented by lower pH. Moreover, Rlx-RGD-CHNPs significantly inhibited breast cancer cell migration and angiogenesis. In vivo studies showed that Cy5.5 conjugated RGD-CHNPs can distinctly visualize tumors and Rlx-RGD-CHNPs significantly inhibit breast tumor growth without causing any toxic effect to normal tissue as confirmed by hematology and blood biochemical studies. Therefore, RGD-CHNPs could potentially enhance the therapeutic efficacy of chemotherapeutic drugs due to the synergistic effect of pH responsiveness and tumor specific targeting in breast cancer.

Recent advantage of hyaluronic acid for anti-cancer application: a review of "3S" transition approach

In recent years, nano drug delivery system has been widely concerned because of its good therapeutic effect. However, the process from blood circulation to cancer cell release of nanodrugs will be eliminated by the human body's own defense trap, thus reducing the therapeutic effect. In recent years, a "3S" transition concept, including stability transition, surface transition and size transition, was proposed to overcome the barriers in delivery process. Hyaluronic (HA) acid has been widely used in delivery of anticancer drugs due to its excellent biocompatibility, biodegradability and specific targeting to cancer cells. In this paper, the strategies and methods of HA-based nanomaterials using "3S" theory are reviewed. The applications and effects of "3S" modified nanomaterials in various fields are also introduced.

Development of synthetic high-density lipoprotein-based ApoA-I mimetic peptide-loaded docetaxel as a drug delivery nanocarrier for breast cancer chemotherapy

In this study, a synthetic high-density lipoprotein (sHDL), peptide-based nanocarrier loaded with docetaxel (DTX) was constructed, against breast cancer. The thermodynamic and molecular dynamic analyses were conducted to examine the stability of nanoparticles synthesized from mimetic peptide 5 A and various types of phospholipids. Furthermore, the cellular uptake and in vivo fluorescence imaging analysis experiments, with scavenger receptor B-I (SR-BI) were carried out to examine the tumor-targeting ability of sHDL. The nanoparticles were investigated for their pharmacodynamic and cytotoxic effects to show their effectivity as anti-tumor agents. The results showed that the synthesized sHDL nanoparticles exhibited a high payload of DTX, sustained drug release properties, and excellent biocompatibility. Moreover, DTX-sHDL nanoparticles enhanced the uptake of DTX, increased the cytotoxicity against MCF-7 cells, and reduced the off-target side-effects to normal cells. Finally, experiments in 4T1 cell line-bearing mice indicate that inhibition of tumor growth by DTX-sHDL nanoparticles was superior to that of free DTX group. Thus, the sHDL nanoparticles are a promising drug delivery vehicle for improving the efficacy of anti-cancer drugs.

Docetaxel-loaded D-α-tocopheryl polyethylene glycol-1000 succinate liposomes improve lung cancer chemotherapy and reverse multidrug resistance

In this study, D-alpha-tocopheryl polyethylene glycol-1000 succinate (TPGS)-coated docetaxel-loaded liposomes were developed to reverse multidrug resistance (MDR) and enhance lung cancer therapy. Evaluations were performed using human lung cancer A549 and resistant A549/DDP cells. The reversal multidrug resistant effect was assessed by P-gp inhibition assay, cytotoxicity, cellular uptake, and apoptosis assay. The tumor xenograft model was built by subcutaneous injection of A549/DDP cells in the right dorsal area of nude mice. The tumor volumes and body weights were measured every other day. The TPGS-coated liposomes showed a concentration- and time-dependent cytotoxicity and significantly enhanced the cytotoxicity of docetaxel in A549/DDP cells. Confocal laser scanning images indicated that higher concentrations of coumarin-6 were successfully delivered into the cytoplasm, and the TPGS-coated liposomes enhanced intracellular drug accumulation by inhibiting overexpressed P-glycoprotein. The TPGS-coated liposomes were shown to induce apoptosis. Furthermore, in vivo anti-tumor studies revealed that TPGS-coated docetaxel-loaded liposomes had outstanding anti-tumor efficacy in an A549/DDP xenograft model. The TPGS-coated liposomes, compared with PEG-coated liposomes, showed significant advantages in vitro and in vivo. The TPGS-coated liposomes were able to reverse MDR and enhance lung cancer therapy. Graphical abstract .

Development and application of hyaluronic acid in tumor targeting drug delivery

Hyaluronic acid (HA) is a natural polysaccharide that has gained much attention due to its biocompatibility, enzyme degradation capacity and active tumor targeting capacity. Its receptor, CD44, is overexpressed in many kinds of cancers and is associated with tumor progress, infiltration and metastasis. Therefore, many researchers have developed various HA-based drug delivery systems for CD44-mediated tumor targeting. In this review, we systemically overview the basic theory of HA, its receptor and hyaluronidase, then we categorize the studies in HA-based drug delivery systems according to the functions of HA, including tumor-targeting materials, enzyme-sensitive biodegradable modality, pH-sensitive component, reduction-sensitive component, and the gel backbone. Finally, the perspective is discussed.

Topological Indices of Hyaluronic Acid-Paclitaxel Conjugates’ Molecular Structure in Cancer Treatment

A large number of medical experiments have confirmed that the features of drugs have a close correlation with their molecular structure. Drug properties can be obtained by studying the molecular structure of corresponding drugs. The calculation of the topological index of a drug structure enables scientists to have a better understanding of the physical chemistry and biological characteristics of drugs. In this paper, we focus on Hyaluronic Acid-Paclitaxel conjugates which are widely used in the manufacture of anticancer drugs. Several topological indices are determined by virtue of the edge-partition method, and our results remedy the lack of medicine experiments, thus providing a theoretical basis for pharmaceutical engineering.

Prognostic Value of CD44 and Its Isoforms in Advanced Cancer: A Systematic Meta-Analysis With Trial Sequential Analysis

Objective: Cancer stem cell marker CD44 and its variant isoforms (CD44v) may be correlated with tumor growth, metastasis, and chemo-radiotherapy resistance. However, the prognostic power of CD44 and CD44v in advanced cancer remains controversial. Therefore, the purpose of our study was to generalize the prognostic significance of these cancer stem cell markers in advanced cancer patients.

Methods: Hazard ratios (HRs) with 95% confidence intervals (95% CIs) were calculated from multivariable analysis to assess the associations among CD44, CD44v6, and CD44v9 positivity and overall survival (OS), disease-free survival (DFS), progression-free survival (PFS), cancer-specific survival (CSS), and recurrence-free survival (RFS). Trial sequential analysis (TSA) was also conducted.

Results: We included 15 articles that reported on 1,201 patients with advanced cancer (CD44: nine studies with 796 cases, CD44v6: three studies with 143 cases, and CD44v9: three studies with 262 cases). CD44 expression was slightly linked to worse OS (HR = 2.03, P = 0.027), but there was no correlation between CD44 expression and DFS, RFS, or PFS. Stratified analysis showed that CD44 expression was not correlated with OS at ≥5 years or OS in patients receiving adjuvant therapy. CD44v6 expression was not associated with OS. CD44v9 expression was closely associated with poor 5-years CSS in patients treated with chemo/radiotherapy (HR = 3.62, P < 0.001). However, TSA suggested that additional trials were needed to confirm these conclusions.

Conclusions: CD44 or CD44v9 might be novel therapeutic targets for improving the treatment of advanced cancer patients. Additional prospective clinical trials are strongly needed across different cancer types.

Chitosan-Based Nanomaterials for Drug Delivery

This review discusses different forms of nanomaterials generated from chitosan and its derivatives for controlled drug delivery. Nanomaterials are drug carriers with multiple features, including target delivery triggered by environmental, pH, thermal responses, enhanced biocompatibility, and the ability to cross the blood-brain barrier. Chitosan (CS), a natural polysaccharide largely obtained from marine crustaceans, is a promising drug delivery vector for therapeutics and diagnostics, owing to its biocompatibility, biodegradability, low toxicity, and structural variability. This review describes various approaches to obtain novel CS derivatives, including their distinct advantages, as well as different forms of nanomaterials recently developed from CS. The advanced applications of CS-based nanomaterials are presented here in terms of their specific functions. Recent studies have proven that nanotechnology combined with CS and its derivatives could potentially circumvent obstacles in the transport of drugs thereby improving the drug efficacy. CS-based nanomaterials have been shown to be highly effective in targeted drug therapy.

Enhanced bioreduction-responsive diselenide-based dimeric prodrug nanoparticles for triple negative breast cancer therapy

Efficient drug accumulation in tumor is essential for chemotherapy. We developed redox-responsive diselenide-based high-loading prodrug nanoparticles (NPs) for targeted triple negative breast cancer (TNBC) treatment. Method: Redox-responsive diselenide bond (Se-Se) containing dimeric prodrug (PTXD-Se) was synthesized and co-precipitated with TNBC-targeting amphiphilic copolymers to form ultra-stable NPs (uPA-PTXD NPs). The drug loading capacity and redox-responsive drug release behavior were studied. TNBC targeting effect and anti-tumor effect were also evaluated in vitro and in vivo.Results: On-demand designed paclitaxel dimeric prodrug could co-precipitate with amphiphilic copolymers to form ultra-stable uPA-PTXD NPs with high drug loading capacity. Diselenide bond (Se-Se) in uPA-PTXD NPs could be selectively cleaved by abnormally high reduced potential in tumor microenvironment, releasing prototype drug, thus contributing to improved anti-cancer efficacy. Endowed with TNBC-targeting ligand uPA peptide, uPA-PTXD NPs exhibited reduced systemic toxicity and enhanced drug accumulation in TNBC lesions, thus showed significant anti-tumor efficacy both in vitro and in vivo. Conclusion: The comprehensive advantage of high drug loading, redox-controlled drug release and targeted tumor accumulation suggests uPA-PTXD NPs as a highly promising strategy for effective TNBC treatment.

Fine Tuning of Core-Shell Structure of Hyaluronic Acid/Cell-Penetrating Peptides/siRNA Nanoparticles for Enhanced Gene Delivery to Macrophages in Antiatherosclerotic Therapy

Hyaluronic-acid (HA)-coated LOX-1-specific siRNA-condensed cell-penetrating peptide (CPP) nanocomplexes (NCs) were developed for targeted gene delivery to macrophages and suppression of lipid accumulation. The HA coating facilitated the accumulation of nanoparticles at leaky endothelium overexpressing CD44 receptors and was further degraded by hyaluronidase (HAase) intraplaques for exposing the naked CPP NCs and achieving the ultimate location into macrophages. The surface coating of HA was verified by the increased particle size, inverted zeta potential, and TEM images. The targeting mechanism was studied on the established injured endothelium-macrophage coculture system, which revealed that modification of higher molecular weight HA and higher HA coating density on NCs, termed as NPs-3, improved the intracellular uptake of nanoparticles by macrophages. Macrophages internalized NCs via caveolae-mediated endocytosis pathway. Moreover, NPs-3 exhibited better cellular drug efficacy in preventing macrophage-derived foam cell formation than other preparations. Compared with NCs, HA decoration showed enhanced atherosclerotic-lesion-targeting efficiency, proven by results from ex vivo imaging. Furthermore, atheroprotective efficacy study in apoE-deficient mice showed that NPs-3 had the best potent efficacy, which was demonstrated by the fewest atherosclerotic lesions sizes and lipid accumulation, the lowest macrophage infiltration, and the lowest expression of monocyte chemoattractant protein-1 (MCP-1), respectively. Collectively, the HA-coated CPP NCs were promising nanocarriers for efficient macrophage-targeted gene delivery and antiatherogenic therapy.