Hyaluronic Acid-Coated Camptothecin Nanocrystals for Targeted Drug Delivery to Enhance Anticancer Efficacy

Applications and advancements of polysaccharide-based nanostructures for enhanced drug delivery

Growing demand for highly effective, site-specific delivery of pharmaceuticals and nutraceuticals using nano-sized carriers has prompted increased scrutiny of carrier biocompatibility and biodegradability. To address these concerns, biodegradable natural polymers have emerged as a transformative domain, offering non-toxic, precisely targetable carriers capable of finely modulating cargo pharmacokinetics while generating innocuous decomposition by-products. This comprehensive review illuminates the emergence of polysaccharide-based nanoparticulate drug delivery systems. These systems establish an interactive interface between drug and targeted organs, guided by strategic modifications to polysaccharide backbones, which facilitate the creation of morphologically, constitutionally, and characteristically vibrant nanostructures through various fabrication routes, underpinning their pivotal role in biomedical applications. Advancements crucial to enhancing polysaccharide-based drug delivery, such as surface modifications and bioinspired modifications for enhanced targeting, and stimuli-responsive release, strategies to overcome biological barriers, enhance tumor penetration, and optimize therapeutic outcomes are highlighted. This review also examines some potent challenges, and the contemporary way out of them, and discusses future perspectives in the field.

Phospholipid-inspired alkoxylation induces crystallization and cellular uptake of luminescent COF nanocarriers

The porous nature and structural variability of covalent organic frameworks (COFs) make them preferred for drug loading and delivery applications. However, most COF materials suffer from poor luminescent properties and inefficiency for cell uptake. Herein, we experimentally demonstrate the crucial role of long alkoxy chains in the synthesis of crystalline COF nanostructures with high cellular uptake efficiency. After luminescence integration through band engineering, the semiconducting COF exhibits an optical bandgap of 2.05 eV, an emission wavelength of 632 nm, a high quantum yield of 37 %, and excellent fluorescence stability (100 % at 3 h). Such excellent optical properties of the designed COF nanocarriers enable quantitative evaluations of cellular uptake and visual tracking of drug delivery. It was demonstrated that the cellular uptake efficiency was enhanced by orders of magnitude for the COF after the introduction of long n-octyloxy chains, which firstly delivered the anticancer camptothecin (CPT) to cell lysosomes, and then underwent "endo/lysosomal escape" to induce cell apoptosis. In vivo assay evidenced a significant enhancement in the therapeutic effect with a 96 % inhibition of tumor growth after 14 days of treatment. This progress sheds light on designing cutting-edge drug delivery nanosystems based on COF materials with integrated diagnostic and therapeutic functions.

Hyaluronan-based nano-formulation with mesoporous silica enhances the anticancer efficacy of phloroglucinol against gastrointestinal cancers

Gastrointestinal cancers are one among the most frequently reported cancers where colorectal and gastric cancers ranks third leading cause of cancer related death worldwide. Phloroglucinol, a well-known therapeutic agent for cancer, where its usage has been limited due to its poor water solubility and bioavailability. Hence, our study aims to synthesize and characterize Hyaluronan grafted phloroglucinol loaded Mesoporous silica nanoparticles (MSN-PG-HA). Our nano-formulation hasn't shown any teratogenic effect on Zebrafish embryos, no hemolysis and toxic effect with normal fibroblast cells with a maximum concentration of 300 μg/mL. The cumulative drug release profile of MSN-PG-HA showed a maximum drug release of 96.9 % with 5 mM GSH under redox responsive drug release, which is crucial for targeting cancer cells. In addition, the MSN-PG-HA nanoparticles showed significant a cytotoxic effect against HCT-116, AGS and SW-620 with IC50 values of 86.5 μg/mL, 80.65 μg/mL and 109.255 μg/mL respectively. Also, the cellular uptake assay has shown an increased uptake of FITC-labeled-MSN-PG-HA by HA-receptor mediated endocytosis than FITC-labeled-MSN-PG without HA modification in CD44+ gastrointestinal cancer cell lines. The ability of MSN-PG-HA to target CD44+ cells was further exploited for its application in cancer stem cell research utilizing in silico analysis with various stem cell pathway related targets, in which PG showed higher binding affinity with Gli 1 and the simulation studies proving its effectiveness in disrupting the protein structure. Thus, the findings of our study with nano-formulation are safe and non-toxic to recommend for targeted drug delivery against gastrointestinal cancers as well as its affinity towards cancer stem cell pathway related proteins proving to be a significant formulation for cancer stem cell research.

Novel pH-responsive alginate-stabilized curcumin-selenium-ZIF-8 nanocomposites for synergistic breast cancer therapy

In this study, a novel selenium@zeolitic imidazolate framework core/shell nanocomposite stabilised with alginate was used to improve the anti-tumour activity of curcumin. The developed alginate-stabilised curcumin-loaded selenium@zeolitic imidazolate framework (Alg@Cur@Se@ZIF-8) had a mean diameter of 159.6 nm and polydispersity index < 0.25. The release of curcumin from the nanocarrier at pH 5.4 was 2.69 folds as high as at pH 7.4. The bare nanoparticles showed haemolytic activity of about 12.16% at a concentration of 500 µg/mL while covering their surface with alginate reduced this value to 5.2%. By investigating cell viability, it was found that Alg@Cur@Se@ZIF-8 caused more cell death than pure curcumin. Additionally, in vivo studies showed that Alg@Cur@Se@ZIF-8 dramatically reduced tumour growth compared to free curcumin in 4T1 tumour-bearing mice. More importantly, the histological study confirmed that the developed drug delivery system successfully inhibited lung and liver metastasis while causing negligible toxicity in vital organs. Overall, due to the excellent inhibitory activity on cancerous cell lines and tumour-bearing animals, Alg@Cur@Se@ZIF-8 can be considered promising for breast cancer therapy.

Bimetallic Gold/Silver and Bioactive Camptothecin Hybrid Nanoparticles for Eradication of Cancer Stem Cells in a Combination Manner

The defeat of cancer is still a challenge due to the existence of cancer stem cells (CSCs) because they resist conventional chemotherapy via multifactor regulated mechanisms. Consequently, one-dimensional action toward CSCs cannot work. Herein, we used rationally designed hybrid nanoparticles as a combined cancer therapy, hoping to form a multidimensional control network. In this paper, gold/silver alloy nanoparticle decorated camptothecin nanocrystals were formulated according to complementary anti-CSC mechanisms from gold, silver, and organic drug. This smart drug formulation could combine chemotherapy and thermotherapy, target different tumor sites, and demonstrate versatile toxicity profiles from each component. Major results indicated that this nanosystem demonstrated indiscriminately effective cytotoxic/proapoptotic/necrotic activity against bulk MCF-7 cells and their CSC subpopulation, in particular under laser ablation. Moreover, this nanosystem displayed enhanced antineoplastic activity against CSC spheroids, resulting in a significant reduction in their number and size, that is, their self-renewal capacity. All the results indicated that CSCs upon treatment of these new hybrid nanoparticles underwent reduced stemness and conversion from the original quiescent state and recovered their sensitivity toward chemotherapy. The relevant anticancer mechanism was ascribed to NIR-pH dual responsive drug release, synergistic/combined thermo-chemotherapy of organic drug and inorganic alloy nanoparticles, enhanced cellular uptake mediated by alloy nanoparticles, and Ag+-induced biomembrane damage. This thermo-chemotherapy platform provides a new combinatorial strategy for inorganic and organic agents in the complete elimination of CSCs.

Red-Fluorescent Covalent Organic Framework Nanospheres for Trackable Anticancer Drug Delivery

Covalent organic frameworks (COFs) have emerged as promising drug carriers due to their structural variability, inherent porosity, and customizable functions. However, most COFs used in drug delivery suffer from low cellular bioavailability and poor luminescence properties. In this study, we designed a series of size-tunable, crystalline, and red-fluorescent COF nanospheres (COFNSs) for trackable anticancer drug delivery. The semiconducting COFNSs were prepared by condensations of 1,3,5-triformylbenzene (TFB) with various dihydrazide blocks through the Schiff-base reaction, resulting in red emission at 647 nm and excellent fluorescence stability (∼100% for 1 h). Such fluorescence property allowed for systematic investigation of the cellular endocytosis pathway of COFNSs, visualization of drug delivery, and observation of the cell apoptosis process. The COFNSs exhibited high cell viability (>90%), a loading capacity of 183 wt % for the anticancer drug camptothecin (CPT), and significant enhancement in inhibiting 4T1 cancers both in vitro and in vivo as the CPT nanocarrier. This progress presents a valuable approach to design COF nanocarriers with integrated fluorescent and drug delivery functions.

Targeted delivery of genistein for pancreatic cancer treatment using hyaluronic-coated cubosomes bioactivated with frankincense oil

Pancreatic cancer is an aggressive malignancy that remains a major cause of cancer-related deaths. Research for innovative anticancer therapeutic options is thus imperative. In this regard, phytotherapeutics offer great promise as efficient treatment modalities, especially leveraging nanodrug delivery. Herein, we innovatively coloaded the flavonoid genistein (Gen) and frankincense essential oil (FO) within cubosomes, which were then coated with the bioactive ligand hyaluronic acid (HA/Gen-FO-Cub) for active-targeting of pancreatic cancer. The novel HA/Gen-FO-Cub displayed optimum nanosize (198.2 ± 4.5 nm), PDI (0.27 ± 0.01), zeta-potential (-34.7 ± 1.2 mV), Gen entrapment (99.3 ± 0.01 %), and controlled Gen release (43.7 ± 1.2 % after 120 h). HA/Gen-FO-Cub exerted selective anticancer activity on pancreatic cancer cells (PANC-1; 8-fold drop in IC50), cellular uptake and anti-migratory effect compared to Gen solution. HA/Gen-FO-Cub revealed prominent cytocompatibility (100 ± 5.9 % viability of human dermal fibroblast). Moreover, HA/Gen-FO-Cub boosted the in vivo anticancer activity of Gen in an orthotopic cancer model, affording tumor growth suppression (2.5-fold drop) and downregulation of NFκB and VEGF (2.9- and 1.8-fold decrease, respectively), compared to Gen suspension. Antimetastatic efficacy and Bcl-2-downexpression was histologically confirmed. Our findings demonstrate the promising anticancer aptitude of HA/Gen-FO-Cub as an effective phytotherapeutic nanodelivery system for pancreatic cancer therapy.

Role of Phytoconstituents in Cancer Treatment: A Review

Over the years, natural compounds have become a significant advancement in cancer treatment, primarily due to their effectiveness, safety, bio-functionality, and wide range of molecular structures. They are now increasingly preferred in drug discovery due to these attributes. These compounds, whether occurring naturally or with synthetic modifications, find applications in various fields like biology, medicine, and engineering. While chemotherapy has been a successful method for treating cancer, it comes with systemic toxicity. To address this issue, researchers and medical practitioners are exploring the concept of combinational chemotherapy. This approach aims to reduce toxicity by using a mix of natural substances and their derivatives in clinical trials and prescription medications. Among the most extensively studied natural anticancer compounds are quercetin, curcumin, vincristine, and vinblastine. These compounds play crucial roles as immunotherapeutics and chemosensitizers, both as standalone treatments and in combination therapies with specific mechanisms. This review article provides a concise overview of the functions, potentials, and combinations of natural anticancer compounds in cancer treatment, along with their mechanisms of action and clinical applications.

Recent advances of nanocrystals in cancer theranostics

Emerging cancer cases across the globe and treating them with conventional therapies with multiple limitations have been challenging for decades. Novel drug delivery systems and alternative theranostics are required for efficient detection and treatment. Nanocrystals (NCs) have been established as a significant cancer diagnosis and therapeutic tool due to their ability to deliver poorly water-soluble drugs with sustained release, low toxicity, and flexibility in the route of administration, long-term sustainable drug release, and noncomplicated excretion. This review summarizes several therapies of NCs, including anticancer, immunotherapy, radiotherapy, biotheranostics, targeted therapy, photothermal, and photodynamic. Further, different imaging and diagnostics using NCs are mentioned, including imaging, diagnosis through magnetic resonance imaging (MRI), computed tomography (CT), biosensing, and luminescence. In addition, the limitations and potential solutions of NCs in the field of cancer theranostics are discussed. Preclinical and clinical data depicting the importance of NCs in the spotlight of cancer, its current status, future aspects, and challenges are covered in detail.

Intravenous nanocrystals: fabrication, solidification, in vivo fate, and applications for cancer therapy

INTRODUCTION

Intravenous nanocrystals (INCs) have shown intrinsic advantages in antitumor applications, particularly their properties of high drug loading, low toxicity, and controllable size. Therefore, it has a very bright application prospect as a drug delivery system.

AREAS COVERED

The ideal formulation design principles, fabrication, solidification, in vivo fate of INCs, the applications in drug delivery system (DDS) and the novel applications are covered in this review.

EXPERT OPINION

It is vital to select a suitable formulation and fabrication method to produce a stable and sterile INCs. Besides, the type of stabilizers and physical characteristics can also influence the in vivo fate of INCs, which is worthy of further studying. Based on wide researches about applications of INCs in cancer, biomimetic INCs are concerned increasingly for its favorable compatibility. The output of these studies suggested that INCs-based drug delivery could be a novel strategy for addressing the delivery of the drug that faces solubility, bioavailability, and toxicity problems.

Phytochemicals and Cancer Treatment: Cell-Derived and Biomimetic Vesicles as Promising Carriers

The majority of anticancer agents currently used derive from natural sources: plants, frequently the ones employed in traditional medicines, are an abundant source of mono- and diterpenes, polyphenols, and alkaloids that exert antitumor activity through diverse mechanisms. Unfortunately, many of these molecules are affected by poor pharmacokinetics and limited specificity, shortcomings that may be overcome by incorporating them into nanovehicles. Cell-derived nanovesicles have recently risen to prominence, due to their biocompatibility, low immunogenicity and, above all, targeting properties. However, due to difficult scalability, the industrial production of biologically-derived vesicles and consequent application in clinics is difficult. As an efficient alternative, bioinspired vesicles deriving from the hybridization of cell-derived and artificial membranes have been conceived, revealing high flexibility and appropriate drug delivery ability. In this review, the most recent advances in the application of these vesicles to the targeted delivery of anticancer actives obtained from plants are presented, with specific focus on vehicle manufacture and characterization, and effectiveness evaluation performed through in vitro and in vivo assays. The emerging overall outlook appears promising in terms of efficient drug loading and selective targeting of tumor cells, suggesting further engrossing developments in the future.

Recent advances in SN-38 drug delivery system

DNA topoisomerase I plays a key role in lubricatingthe wheels of DNA replication or RNA transcription through breaking and reconnecting DNA single-strand. It is widely known that camptothecin and its derivatives (CPTs) have inhibitory effects on topoisomerases I, and have obtained some clinical benefits in cancer treatment. The potent cytotoxicity makes 7-ethyl-10-hydroxycamptothecin (SN-38) become a brilliant star among these derivatives. However, some undesirable physical and chemical properties of this compound, including poor solubility and stability, seriously hinder its effective delivery to tumor sites. In recent years, strategies to alleviate these defects have aroused extensive research interest. By focusing on the loading mechanism, basic nanodrug delivery systems with SN-38 loaded, like nanoparticles, liposomes and micelles, are demonstrated here. Additionally, functionalized nanodrug delivery systems of SN-38 including prodrug and active targeted nanodrug delivery systems and delivery systems designed to overcome drug resistance are also reviewed. At last, challenges for future research in formulation development and clinical translation of SN-38 drug delivery system are discussed.

Natural Products as Anticancer Agents: Current Status and Future Perspectives

Natural products have been an invaluable and useful source of anticancer agents over the years. Several compounds have been synthesized from natural products by modifying their structures or by using naturally occurring compounds as building blocks in the synthesis of these compounds for various purposes in different fields, such as biology, medicine, and engineering. Multiple modern and costly treatments have been applied to combat cancer and limit its lethality, but the results are not significantly refreshing. Natural products, which are a significant source of new therapeutic drugs, are currently being investigated as potential cytotoxic agents and have shown a positive trend in preclinical research and have prompted numerous innovative strategies in order to combat cancer and expedite the clinical research. Natural products are becoming increasingly important for drug discovery due to their high molecular diversity and novel biofunctionality. Furthermore, natural products can provide superior efficacy and safety due to their unique molecular properties. The objective of the current review is to provide an overview of the emergence of natural products for the treatment and prevention of cancer, such as chemosensitizers, immunotherapeutics, combinatorial therapies with other anticancer drugs, novel formulations of natural products, and the molecular mechanisms underlying their anticancer properties.

An Overview of Antitumour Activity of Polysaccharides

Cancer incidence and mortality are rapidly increasing worldwide; therefore, effective therapies are required in the current scenario of increasing cancer cases. Polysaccharides are a family of natural polymers that hold unique physicochemical and biological properties, and they have become the focus of current antitumour drug research owing to their significant antitumour effects. In addition to the direct antitumour activity of some natural polysaccharides, their structures offer versatility in synthesizing multifunctional nanocomposites, which could be chemically modified to achieve high stability and bioavailability for delivering therapeutics into tumor tissues. This review aims to highlight recent advances in natural polysaccharides and polysaccharide-based nanomedicines for cancer therapy.

Green Synthesis of Gold Nanoparticles and Study of Their Inhibitory Effect on Bulk Cancer Cells and Cancer Stem Cells in Breast Carcinoma

Chemo-resistance from cancer stem cells (CSCs) subpopulation is a current issue in cancer treatment. It is important to select alternative therapies to efficiently eradicate both bulk cancer cells and CSCs. Here, gold nanoparticles (AuNPs) have been selected regarding their biocompatibility, facile and controllable synthesis, potent anti-cancer activity and photothermal conversion performance. We reported a green synthesis of functionalized AuNPs using hyaluronic acid (HA) as a reductant, capping, stabilizing and hydrophilic substance. The resultant AuNPs were spherical-shaped with an average diameter of around 30 nm. These AuNPs displayed improved physico-chemical (yield, stability, photothermal effect) and biological properties (cellular uptake, cytotoxicity and apoptotic effect) against bulk MDA-MB-231 cells, in comparison with other organic anti-cancer drugs. The intensified bioactivity was dependent on a mitochondria-mediated cascade, reflected by the damage in mitochondria, oxidative stress, intensified Caspase 3 activity and increased/decreased expression of certain pro-apoptotic (Bax, P53, Caspase 3)/anti-apoptotic (Bcl-2) genes. Moreover, these AuNPs posed a dramatically improved inhibitory effect in cell viability and self-renewable capacity on CSC subpopulation. All the results were attributed from the nano-scaled structure of AuNPs and combined effect from NIR-induced hyperthermia. In addition, the biocompatible nature of these AuNPs supported them to be a potential candidate in the development of novel chemotherapeutic drugs.

Nano- and Crystal Engineering Approaches in the Development of Therapeutic Agents for Neoplastic Diseases

Cancer is a leading cause of death worldwide. It is a global quandary that requires the administration of many different active pharmaceutical ingredients (APIs) with different characteristics. As is the case with many APIs, cancer treatments exhibit poor aqueous solubility which can lead to low drug absorption, increased doses, and subsequently poor bioavailability and the occurrence of more adverse events. Several strategies have been envisaged to overcome this drawback, specifically for the treatment of neoplastic diseases. These include crystal engineering, in which new crystal structures are formed to improve drug physicochemical properties, and/or nanoengineering in which the reduction in particle size of the pristine crystal results in much improved physicochemical properties. Co-crystals, which are supramolecular complexes that comprise of an API and a co-crystal former (CCF) held together by non-covalent interactions in crystal lattice, have been developed to improve the performance of some anti-cancer drugs. Similarly, nanosizing through the formation of nanocrystals and, in some cases, the use of both crystal and nanoengineering to obtain nano co-crystals (NCC) have been used to increase the solubility as well as overall performance of many anticancer drugs. The formulation process of both micron and sub-micron crystalline formulations for the treatment of cancers makes use of relatively simple techniques and minimal amounts of excipients aside from stabilizers and co-formers. The flexibility of these crystalline formulations with regards to routes of administration and ability to target neoplastic tissue makes them ideal strategies for effectiveness of cancer treatments. In this review, we describe the use of crystalline formulations for the treatment of various neoplastic diseases. In addition, this review attempts to highlight the gaps in the current translation of these potential treatments into authorized medicines for use in clinical practice.

Using Amphiphilic Polymer Micelles as the Templates of Antisolvent Crystallization to Produce Drug Nanocrystals

Biocompatible and biodegradable amphiphilic polymeric micelles (PLA-CMCS-g-OA) were prepared by surface grafting of oleic acid and polylactic acid onto carboxymethyl chitosan and were used as templates for the crystallization of camptothecin. The camptothecin (CPT) nanocrystals prepared by the novel micelle-templated antisolvent crystallization (mt-ASC) method demonstrated higher crystallinity, narrower particle size distribution, and slower release characteristic than those prepared by conventional antisolvent crystallization (c-ASC) using a high initial concentration and fast addition rate. In particular, the CPT release behavior of mt-ASC products in phosphate buffer solutions presented a pH-responsive characteristic with the increasing release rate of CPT under lower pH conditions. This work confirmed that amphiphilic nanomicelle-templated crystallization was an effective method for preparing drug nanocrystals.

Dual-targeted and controlled release delivery of doxorubicin to breast adenocarcinoma: In vitro and in vivo studies

Doxorubicin (DOX) is a chemotherapeutic drug that belongs to the anthracyclines family. Cardiotoxicity is one of the main limiting factor of prescribing DOX. To reduce its side effects and enhance the drug delivery to the targeted tissues, we aimed to establish a new targeted and controlled release drug delivery system for treatment of breast cancer. In this article, we tried to synthesize a new nanoplatform consisted of DOX conjugate with hydrazide and disulfide bonds to the hyaluronic acid (HA). Firstly, 4,4'-Dithiodibutyric acid (DTBH) was conjugated with HA. Then, 3-aminophenyl boronic acid monohydrate (APBA) was conjugated with DTBH-HA. Subsequently, DOX was added to DTBH-HA-APBA. HA is a natural polymer with the ability to target CD44, a cell surface adhesion receptor, which are highly overexpressed on the surface of variety of cancer cells. Other targeting agent, APBA can target sialic acid on the cancer cells surface and improve the tumor uptake. Formation of The DTBH-HA-APBA conjugate was confirmed by proton nuclear magnetic resonance (¹H-NMR) spectroscopy. Scanning emission electron microscopy (SEM) images of the DOX-DTBH-HA-APBA displayed a spherical shape with an average diameter of about 70 nm. In vitro drug release study showed considerably different release pattern of DOX from the formulation at acidic pH (5.4) which was higher than normal pH (7.4). Cellular uptake and cellular cytotoxicity analysis were examined in human breast adenocarcinoma cell line (MCF-7) and mouse breast cancer cells (4T1) as positive cell lines and Chinese Hamster Ovary cells (CHO) as negative cell line. Results confirmed that there is a remarkable difference between dual-targeted (DOX-DTBH-HA-APBA) and single targeted (DOX-DTBH-HA) formulations in both positive cell lines regarding internalization and cytotoxicity. In vivo studies indicated that dual-targeted formulation has the best efficacy with minimum side effects in mouse model. Fluorescence imaging of organs revealed that DOX-DTBH-HA-APBA showed greater DOX accumulation compared with DOX-DTBH-HA and free DOX in tumor site. Also, pathological evaluation indicated that there is no observable cardiotoxicity with final formulation.

Gold Nanoparticle-Decorated Drug Nanocrystals for Enhancing Anticancer Efficacy and Reversing Drug Resistance Through Chemo-/Photothermal Therapy

Limited chemotherapeutic efficiency, drug resistance, and side effects are primary obstacles for cancer treatment. The development of co-delivery systems with synergistic treatment modes should be a promising strategy. Here, we fabricated a multifunctionalized nanocarrier with a combination of chemotherapeutic agents and gold nanoparticles (AuNPs), which could integrate chemo-photothermal therapy, thus enhancing overall anticancer efficacy, sensitizing drug-resistant cancer cells, and diminishing cancer stem cells (CSCs). To be specific, camptothecin nanocrystals (CPT NCs) were prepared as a platform, on the surface of which AuNPs were decorated and a hyaluronic acid layer acted as capping, stabilizing, targeting, and hydrophilic agents for CPT NCs, and reducing agents for AuNPs, providing a bridge connecting AuNPs to CPT. These AuNP-decorated CPT NCs exhibited good physico-chemical properties such as optimal sizes, payload, stability, and photothermal efficiency. Compared to other CPT formulations, they displayed considerably improved biocompatibility, selectivity, intracellular uptake, cytotoxicity, apoptosis induction activity, Pgp inhibitory capability, and anti-CSC activity, owing to a synergistic/cooperative effect from AuNPs, CPT, near-infrared treatment, pH/photothermal-triggered drug release, and nanoscaled structure. A mitochondrial-mediated signaling pathway is the underlying mechanism for cytotoxic and apoptotic effects from AuNP-decorated CPT NCs, in terms of mitochondrial dysfunction, intensified oxidative stress, DNA fragmentation, caspase 3 activation, upregulation of proapoptotic genes such as p53, Bax, and caspase 3, and lower levels of antiapoptotic Bcl-2.

Drug Nanocrystals for Active Tumor-Targeted Drug Delivery

Drug nanocrystals, which are comprised of active pharmaceutical ingredients and only a small amount of essential stabilizers, have the ability to improve the solubility, dissolution and bioavailability of poorly water-soluble drugs; in turn, drug nanocrystal technology can be utilized to develop novel formulations of chemotherapeutic drugs. Compared with passive targeting strategy, active tumor-targeted drug delivery, typically enabled by specific targeting ligands or molecules modified onto the surface of nanomedicines, circumvents the weak and heterogeneous enhanced permeability and retention (EPR) effect in human tumors and overcomes the disadvantages of nonspecific drug distribution, high administration dosage and undesired side effects, thereby contributing to improving the efficacy and safety of conventional nanomedicines for chemotherapy. Continuous efforts have been made in the development of active tumor-targeted drug nanocrystals delivery systems in recent years, most of which are encouraging and also enlightening for further investigation and clinical translation.

A New Gold Nanoparticles and Paclitaxel Co-Delivery System for Enhanced Anti-Cancer Effect Through Chemo-Photothermal Combination

Limited chemotherapeutic efficiency, drug resistance and side effect are primary obstacles for cancer treatment. The development of co-delivery system with synergistic treatment modes should be a promising strategy. Here, we fabricated a multi-functionalized nanocarrier with a combination of chemotherapeutic agent and gold nanoparticles (AuNPs), which could integrate chemo-photothermal therapy and improve entire anti-cancer index. Particularly, Paclitaxel nanocrystals (PTX NC) were first fabricated as a platform, on surface of which AuNPs were decorated and polydopamine (PDA) layer act as capping, stabilizing and hydrophilic agents for PTX NC, providing a bridge connecting AuNPs to PTX. These AuNPs decorated PTX NC exhibited good physico-chemical properties like optimal sizes, stability and photothermal efficiency. Compared to other PTX formulations, they displayed considerably improved biocompatibility, selectivity, intracellular uptake, cytotoxicity, apoptosis induction activity and P-glycoprotein (Pgp) inhibitory capability, owing to a synergistic/ cooperative effect from AuNPs, PTX and NIR treatment, photothermal-triggered drug release and nano-scaled structure. Mitochondria-mediated signaling pathway is underlying mechanism for cytotoxic and apoptotic effect from AuNPs decorated PTX NC, in terms of Mitochondria damage, a loss of Mitochondrial membrane potential, intensified oxidative stress, DNA breakage, Caspase 3 activation, up-regulated expression in pro-apoptotic genes like p53, Caspase 3 and Bax and down-regulated level in anti-apoptotic gene like Bcl-2.

Paclitaxel Drug Delivery Systems: Focus on Nanocrystals' Surface Modifications

Paclitaxel (PTX) is a chemotherapeutic agent that belongs to the taxane family and which was approved to treat various kinds of cancers including breast cancer, ovarian cancer, advanced non-small-cell lung cancer, and acquired immunodeficiency syndrome (AIDS)-related Kaposi’s sarcoma. Several delivery systems for PTX have been developed to enhance its solubility and pharmacological properties involving liposomes, nanoparticles, microparticles, micelles, cosolvent methods, and the complexation with cyclodextrins and other materials that are summarized in this article. Specifically, this review discusses deeply the developed paclitaxel nanocrystal formulations. As PTX is a hydrophobic drug with inferior water solubility properties, which are improved a lot by nanocrystal formulation. Based on that, many studies employed nano-crystallization techniques not only to improve the oral delivery of PTX, but IV, intraperitoneal (IP), and local and intertumoral delivery systems were also developed. Additionally, superior and interesting properties of PTX NCs were achieved by performing additional modifications to the NCs, such as stabilization with surfactants and coating with polymers. This review summarizes these delivery systems by shedding light on their route of administration, the methods used in the preparation and modifications, the in vitro or in vivo models used, and the advantages obtained based on the developed formulations.

Progress and Principle of Drug Nanocrystals for Tumor Targeted Delivery

Drugs are referred to as drug nanocrystals when they exist as nanoscale crystal structures. This kind of nanocarrier has been widely utilized to increase the solubility and absorption for poorly aqueous soluble drugs after oral administration, or prolong the drug circulation when intravenous administration. The systemic cytotoxicity caused by antitumor drugs usually come from the nonspecific drug distribution. To solve the disadvantage of poor targetability, drug nanocrystals for tumor targeted delivery have been developed in recent years. In this review, the targeting mechanisms of various surface modified drug nanocrystals are introduced with the focus on passive targeting, active targeting and stimuli-responsive targeting in details. Function and application of common surface modified materials are also discussed.

Targeted Gold Nanohybrids Functionalized with Folate-Hydrophobic-Quaternized Pullulan Delivering Camptothecin for Enhancing Hydrophobic Anticancer Drug Efficacy

This study presented a green, facile and efficient approach for a new combination of targeted gold nanohybrids functionalized with folate-hydrophobic-quaternized pullulan delivering hydrophobic camptothecin (CPT-GNHs@FHQ-PUL) to enhance the efficacy, selectivity, and safety of these systems. New formulations of spherical CPT-GNHs@FHQ-PUL obtained by bio-inspired strategy were fully characterized by TEM, EDS, DLS, zeta-potential, UV-vis, XRD, and ATR-FTIR analyses, showing a homogeneous particles size with an average size of approximately 10.97 ± 2.29 nm. CPT was successfully loaded on multifunctional GNHs@FHQ-PUL via intermolecular interactions. Moreover, pH-responsive CPT release from newly formulated-CPT-GNHs@FHQ-PUL exhibited a faster release rate under acidic conditions. The intelligent CPT-GNHs@FHQ-PUL (IC50 = 6.2 μM) displayed a 2.82-time higher cytotoxicity against human lung cancer cells (Chago-k1) than CPT alone (IC50 = 2.2 μM), while simultaneously exhibiting less toxicity toward normal human lung cells (Wi-38). These systems also showed specific uptake by folate receptor-mediated endocytosis, exhibited excellent anticancer activity, induced the death of cells by increasing apoptosis pathway (13.97%), and arrested the cell cycle at the G0-G1 phase. The results of this study showed that the delivery of CPT by smart GNHs@FHQ-PUL systems proved to be a promising strategy for increasing its chemotherapeutic effects.

Nanocrystals for Improving Oral Bioavailability of Drugs: Intestinal Transport Mechanisms and Influencing Factors

With the limitation of solubility and dissolution rate of insoluble drugs, following oral administration, they would rifely prove poor and volatile bioavailability, which may fail to realize its therapeutic value. The drug nanocrystals are perceived as effective tactic for oral administration of insoluble drugs attributes to possess many prominent properties such as elevating dissolution rate and saturation solubility, high drug loading capacity, and improving oral bioavailability. Based on these advantages, the application of nanocrystals in oral drug delivery has acquired significant achievement, and so far more than 20 products of drug nanocrystals have been confirmed in the market. However, the oral absorption of drug nanocrystals is still facing huge challenges due to the limitation of many factors. Intrinsic properties of the drugs and complex physiological environment of the intestinal tract are the two most important factors affecting the oral bioavailability of drugs. In addition, the research on the multi-aspect mechanisms of nanocrystals promoting gastrointestinal absorption and bioavailability has been gradually deepened. In this review, we summarized recent advances of the nanocrystals delivered orally, and provided an overview to the research progress for crossing the intestinal tract transport mechanisms of the nanocrystals by some new research techniques. Meanwhile, the factors relevant to the transport of drug nanocrystals were also elaborated in detail. Graphical Abstract.

Fabrication of versatile targeted lipopolymersomes for improved camptothecin efficacy against colon adenocarcinoma in vitro and in vivo

BACKGROUND

Hybrid vesicular systems (lipopolymersomes) are promising platforms for minimizing the liposomes and polymersomes disadvantages in terms of chemotherapeutic transportation. In this regard, lipopolymersome has been designed to integrate the advantage of both polymersomes and liposomes to enable better structural integrity of the bilayer after encapsulation of hydrophobic drugs while maintaining the soft nature of liposomes, superior serum stability, and high encapsulation efficiency of cargos in the bilayer segment.

RESEARCH DESIGN AND METHODS

In the present study, we reported preparation and characterization of five camptothecin (CPT)-loaded lipopolymersomal formulations composed of poly (ethylene glycol)-poly (lactic acid) (PEG-PLA) and dipalmitoylphosphatidylcholine (DPPC) at different molar ratios using film rehydration method. Afterward, the preferred formulation was tagged with AS1411 DNA aptamer in order to evaluate the therapeutic index using nucleolin-positive colon cancer cell lines (HT29 and C26).

RESULTS

The obtained data indicated that the prepared CPT-loaded lipopolymersome at a PEG-PLA: DPPC ratio of 75:25 exhibited superior stability and high loading capacity compared to other systems. Moreover, high cytotoxicity of the aptamer-targeted lipopolymersome and increased tumor accumulation were observed in comparison with non-targeted one.

CONCLUSIONS

The designed polymer-rich lipopolymersomal platform offers bright future for the development of potent nanomedicine against cancer.

Silver nanoparticles functionalized Paclitaxel nanocrystals enhance overall anti-cancer effect on human cancer cells

For chemotherapeutic drugs, precise tumor-targeting and high anti-cancer efficiency is equally important in order to enhance chemotherapy and reverse drug resistance. The combination of multifunctional agents to achieve synergy should be a promising strategy. In our study, we have successfully developed novel multifunctionalized drug nanocrystals to realize co-delivery of the organic drug Paclitaxel (PTX), inorganic silver nanoparticles (AgNPs) and a tumor targeting agent. To be specific, PTX nanocrystals were first prepared as a template, then coated with polydopamine (PDA). The PDA layer was utilized as the connection bridge to produce and deposit AgNPs in situ, and provide sites for tumor-targeting peptide NR1 (RGDARF) grafting. As a result, these NR1/AgNP-decorated drug nanocrystals exhibited dramatically improved cellular uptake efficiency, in vitro anti-cancer activity and an anti-migratory effect against a variety of cancer cells, which was attributable to the synergistic, or at least additive, effect of the AgNPs and PTX, enhanced cellular uptake efficiency through NR1-receptor interaction, pH-responsive drug release and the nanoscaled nature. In particular, high anti-cancer activity and low side effects from these NR1/AgNP-decorated PTX nanocrystals were well balanced in terms of good selectivity and biocompatibility. Moreover, these novel drug nanocrystals displayed strong apoptotic-inducing potency, resulting in cell membrane lysis, nuclear damage, mitochondria dysfunction, excessive ROS release and double-stranded DNA breakage. The potential acting mechanism and molecular basis of these novel drug nanocrystals is relevant to the regulation of mitochondria-mediated apoptosis with a greater Bax-to-Bcl-2 ratio and the activation of pro-apoptotic P53 and caspase 3.