10-Hydroxycamptothecin (HCPT) nanosuspensions stabilized by mPEG1000-HCPT conjugate: high stabilizing efficiency and improved antitumor efficacy

Development of a RNA-protein complex based smart drug delivery system for 9-hydroxycamptothecin

Camptothecin (CPT) is a monoterpenoid indole alkaloid with a wide spectrum of anticancer activity. However, its application is hindered by poor solubility, lack of targeting specificity, and severe side effects. Structural derivatization of CPT and the development of suitable drug delivery systems are potential strategies for addressing these issues. In this study, we discovered that the protein Cytochrome P450 Family 1 Subfamily A Member 1 (CYP1A1) from Homo sapiens catalyzes CPT to yield 9-hydroxycamptothecin (9-HCPT), which exhibits increased water solubility and cytotoxicity. We then created a RNA-protein complex based drug delivery system with enzyme and pH responsiveness and improved the targeting and stability of the nanomedicine through protein module assembly. The subcellular localization of nanoparticles can be visualized using fluorescent RNA probes. Our results not only identified the protein CYP1A1 responsible for the structural derivatization of CPT to synthesize 9-HCPT but also offered potential strategies for enhancing the utilization of silk-based drug delivery systems in tumor therapy.

pH-Responsive Micellar Nanoparticles for the Delivery of a Self-Amplifying ROS-Activatable Prodrug

The objective of this study is to enhance the therapeutic efficacy of the anticancer drug, camptothecin (CPT) via a nanoparticle (NP) formulation using a novel amphiphilic biopolymer. We have designed a dimeric prodrug of CPT with the ability to self-amplify and respond to reactive oxygen species (ROS). For this, we incorporated the intracellular ROS generator cinnamaldehyde into a ROS-cleavable thioacetal (TA) linker to obtain the dimeric prodrug of CPT (DCPT(TA)). For its efficient NP delivery, a pH-responsive block copolymer of acetalated dextran and poly(2-ethyl-2-oxazoline) (AcDex-b-PEOz) was synthesized. The amphiphilic feature of the block copolymer enables its self-assembly into micellar NPs and results in high prodrug loading capacity and a rapid release of the prodrug under acidic conditions. Upon cellular uptake by HeLa cells, DCPT(TA)-loaded micellar NPs induce intracellular ROS generation, resulting in accelerated prodrug activation and enhanced cytotoxicity. These results indicate that this system holds significant potential as an effective prodrug delivery strategy in anticancer treatment.

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.

Novel nano-drug delivery system for natural products and their application

The development of natural products for potential new drugs faces obstacles such as unknown mechanisms, poor solubility, and limited bioavailability, which limit the broadened applicability of natural products. Therefore, there is a need for advanced pharmaceutical formulations of active compounds or natural products. In recent years, novel nano-drug delivery systems (NDDS) for natural products, including nanosuspensions, nanoliposomes, micelle, microemulsions/self-microemulsions, nanocapsules, and solid lipid nanoparticles, have been developed to improve solubility, bioavailability, and tissue distribution as well as for prolonged retention and enhanced permeation. Here, we updated the NDDS delivery systems used for natural products with the potential enhancement in therapeutic efficiency observed with nano-delivery systems.

Biomacromolecule-based nanocarrier strategies to deliver plant-derived bioactive components for cancer treatment: A recent review

The quest for safe chemotherapy has attracted researchers to explore anticancer potential of herbal medicines. Owing to upsurging evidence of herbal drug's beneficial effects, hopes are restored for augmenting survival rates in cancer patients. However, phytoconstituents confronted severe limitations in terms of poor absorption, low-stability, and low bioavailability. Along with toxicity issues associated with phytoconstituents, quality control and limited regulatory guidance also hinder the prevalence of herbal medicines for cancer therapy. Attempts are underway to exploit nanocarriers to circumvent the limitations of existing and new herbal drugs, where biological macromolecules (e.g., chitosan, hyaluronic acid, etc.) are established highly effective in fabricating nanocarriers and cancer targeting. Among the discussed nanocarriers, liposomes and micelles possess properties to cargo hydro- and lipophilic herbal constituents with surface modification for targeted delivery. Majorly, PEG, transferrin and folate are utilized for surface modification to improve bioavailability, circulation time and targetability. The dendrimer and carbon nanotubes responded in high-loading efficiency of phytoconstituent; whereas, SLN and nanoemulsions are suited carriers for lipophilic extracts. This review emphasized unveiling the latent potential of herbal drugs along with discussing on extended benefits of nanocarriers-based delivery of phytoconstituents for safe cancer therapy owing to enhanced clinical and preclinical outcomes without compromising safety.

Herbal Medicine Nanocrystals: A Potential Novel Therapeutic Strategy

Herbal medicines have gained recognition among physicians and patients due to their lower adverse effects compared to modern medicines. They are extensively used to treat various diseases, including cancer, cardiovascular issues, chronic inflammation, microbial contamination, diabetes, obesity, and hepatic disorders, among others. Unfortunately, the clinical application of herbal medicines is limited by their low solubility and inadequate bioavailability. Utilizing herbal medicines in the form of nanocrystals (herbal medicine nanocrystals) has shown potential in enhancing solubility and bioavailability by reducing the particle size, increasing the specific surface area, and modifying the absorption mechanisms. Multiple studies have demonstrated that these nanocrystals significantly improve drug efficacy by reducing toxicity and increasing bioavailability. This review comprehensively examines therapeutic approaches based on herbal medicine nanocrystals. It covers the preparation principles, key factors influencing nucleation and polymorphism control, applications, and limitations. The review underscores the importance of optimizing delivery systems for successful herbal medicine nanocrystal therapeutics. Furthermore, it discusses the main challenges and opportunities in developing herbal medicine nanocrystals for the purpose of treating conditions such as cancer, inflammatory diseases, cardiovascular disorders, mental and nervous diseases, and antimicrobial infections. In conclusion, we have deliberated regarding the hurdles and forthcoming outlook in the realm of nanotoxicity, in vivo kinetics, herbal ingredients as stabilizers of nanocrystals, and the potential for surmounting drug resistance through the utilization of nanocrystalline formulations in herbal medicine. We anticipate that this review will offer innovative insights into the development of herbal medicine nanocrystals as a promising and novel therapeutic strategy.

Functionalized nanoparticles crossing the brain-blood barrier to target glioma cells

Glioma is the most common tumor of the central nervous system (CNS), with a 5-year survival rate of <35%. Drug therapy, such as chemotherapeutic and immunotherapeutic agents, remains one of the main treatment modalities for glioma, including temozolomide, doxorubicin, bortezomib, cabazitaxel, dihydroartemisinin, immune checkpoint inhibitors, as well as other approaches such as siRNA, ferroptosis induction, etc. However, the filter function of the blood-brain barrier (BBB) reduces the amount of drugs needed to effectively target CNS tumors, making it one of the main reasons for poor drug efficacies in glioma. Thus, finding a suitable drug delivery platform that can cross the BBB, increase drug aggregation and retainment in tumoral areas and avoid accumulation in non-targeted areas remains an unsolved challenge in glioma drug therapy. An ideal drug delivery system for glioma therapy should have the following features: (1) prolonged drug life in circulation and effective penetration through the BBB; (2) adequate accumulation within the tumor (3) controlled-drug release modulation; (4) good clearance from the body without significant toxicity and immunogenicity, etc. In this regard, due to their unique structural features, nanocarriers can effectively span the BBB and target glioma cells through surface functionalization, providing a new and effective strategy for drug delivery. In this article, we discuss the characteristics and pathways of different nanocarriers for crossing the BBB and targeting glioma by listing different materials for drug delivery platforms, including lipid materials, polymers, nanocrystals, inorganic nanomaterials, etc.

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.

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.

Advances in Antitumor Nano-Drug Delivery Systems of 10-Hydroxycamptothecin

10-Hydroxycamptothecin (HCPT) is a natural plant alkaloid from Camptotheca that shows potent antitumor activity by targeting intracellular topoisomerase I. However, factors such as instability of the lactone ring and insolubility in water have limited the clinical application of this drug. In recent years, unprecedented advances in biomedical nanotechnology have facilitated the development of nano drug delivery systems. It has been found that nanomedicine can significantly improve the stability and water solubility of HCPT. NanoMedicines with different diagnostic and therapeutic functions have been developed to significantly improve the anticancer effect of HCPT. In this paper, we collected reports on HCPT nanomedicines against tumors in the past decade. Based on current research advances, we dissected the current status and limitations of HCPT nanomedicines development and looked forward to future research directions.

A Water-Soluble Polyacid Polymer Based on Hydrophilic Metal-Organic Frameworks Using Amphoteric Carboxylic Acid Ligands as Linkers for Hydroxycamptothecin Loading and Release In Vitro

The poor water solubility and severe side effects of hydroxycamptothecin (HCPT) limit its clinical application; therefore, it is necessary to synthesize applicable nanodrug carriers with good solubility to expand the applications of HCPT. In this study, a hydrophilic metal-organic framework (MOF) with amphoteric carboxylic acid ligands as linkers was first synthesized and characterized. Then, water-soluble acrylamide and methacrylic acid were applied as monomers to prepare a water-soluble polyacid polymer MOF@P, which had a solubility of 370 μg/mL. The effects of the MOF@P material on the HCPT loading and solubility were investigated. The results showed that the polymer material could improve the HCPT solubility in water. Moreover, the in vitro release study indicated that the MOF@P polymeric composite exhibited a sustained-release effect on HCPT, with a cumulative release rate of 30.18% in 72 h at pH 7.4. Furthermore, the cytotoxicity test demonstrated that the hydrophilic MOF and the MOF@P had low cell toxicities. The results indicate that the prepared MOF@P polymeric complex can be applied for the sustained release of HCPT in clinics.

Improving stability and oral bioavailability of hydroxycamptothecin via nanocrystals in microparticles (NCs/MPs) technology

This study developed a nanocrystals-in-microparticles (NCs/MPs) technology for improving dissolution and oral absorption of poorly soluble drugs. Hydroxycamptothecin (HCPT) was selected as a model drug and prepared to be nanocrystals (HCPT-NCs) by acid-alkali based precipitation. The HCPT-NCs were rod like shape with the length of 250 nm and the width of 50 nm. Then, the chitosan and sodium alginate were selected as microparticles matrix to encapsulate the HCPT-NCs. The HCPT-NCs were entrapped in microparticles with a D₅₀ value of 15 µm. The drug loading capacity of microparticles achieved more than 40% (w/w) by NCs/MPs technology. The powder X-ray diffraction showed the crystal structure of HCPT in microparticles was same as nanocrystals, indicating that the preparation of microparticles could not destroy the nanocrystals. The in vitro release demonstrated that microparticles could protect the NCs in gastric fluid and release NCs in intestinal fluid. Furthermore, the oral bioavailability of HCPT in NCs/MPs was improved by 18-fold compared to bulk HCPT and 2.1-fold compared to HCPT-NCs as tested by a rat model. Therefore, NCs/MPs technology is a promising and high effective approach to improve the oral bioavailability of poorly soluble drugs.

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.

A GSH-Responsive Nanoprodrug System Based on Self-Assembly of Lactose Modified Camptothecin for Targeted Drug Delivery and Combination Chemotherapy

Background

Conventional chemotherapy using small molecular antitumor drugs suffers from several limitations, for instance poor water solubility, high toxicity, and lack of specificity. However, prodrugs constructed by covalent modification of anticancer drugs can overcome these limitations, which are able to release its active form after entering the tumor tissues by specific stimulus response.

Methods

A GSH-responsive glyco-nanoprodrug system has been constructed by self-assembled of amphiphilic lactosemodified camptothecin prodrug molecular (Lac-SS-CPT) for targeting drug delivery and combination therapy.

Results

Using HL7702 cells as experimental models, the cytotoxic effects of Lac-SS-CPT were investigated to 10–30 µmol/L for 48 hours. Notably, the cell viability of Lac-SS-CPT to HL7702 cells was higher compared with free CPT which indicated that Lac-SS-CPT can reduce side-effects. Simultaneously, we have evaluated the anticancer efficiency of doxorubicin hydrochloride (DOX)-loaded Lac-SS-CPT glyco-nanoprodrug system (Lac-SS-CPT@DOX), where Lac-SS-CPT@DOX and free DOX incubated with HpeG2 cells and HL7702 cells for 24, 48, and 72 hours, respectively. It turned out that Lac-SS-CPT@DOX encapsulated anticancer drug (DOX) could decrease DOX side-effect on HL7702 cells and increase DOX anticancer efficiency. More importantly, the CPT and DOX were released from Lac-SS-CPT@DOX in HepG2 cells where a higher GSH concentration exists. Moreover, combination therapy efficiency was evaluated, where free DOX and Lac-SS-CPT@DOX incubated with DOX-resistance HepG2 cells (HepG2-ADR cells), respectively.

Conclusion

The results revealed that the Lac-SS-CPT@DOX could enhance the cytotoxicity of DOX for HepG2-ADR cells and provided a new idea for designing an advanced nano-prodrug system toward combination therapy.

Enhanced Stability of the Pharmacologically Active Lactone Form of 10-Hydroxycamptothecin by Self-Microemulsifying Drug Delivery Systems

10-Hydroxycamptothecin (HCPT) is a DNA inhibitor of topoisomerase I and exerts antitumor activities against various types of cancer. However, reversible conversion from a pharmacologically active lactone form to an inactive carboxylate form of HCPT and poor water solubility hamper its clinical applications. To overcome these shortcomings, we designed a fine self-microemulsifying drug delivery system (SMEDDS) for HCPT to effectively protect HCPT in its active lactone form as well as improving dissolution rates. A formulation of HCPT-SMEDDS that contained ethyl oleate, D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS), and polyethylene glycol 400 (PEG400) was optimized by using the central composite design and response surface methodology. Following 1:100 aqueous dilution of the optimized HCPT-SMEDDS, the droplet size of resulting microemulsions was 25.6 ± 0.7 nm, and the zeta potential was - 15.2 ± 0.4 mV. The optimized HCPT-SMEDDS appeared to stabilize the lactone moiety of HCPT with 73.6% being present in the pharmacologically active lactone forms in simulated intestinal fluid, but only 45.7% for free HCPT. Furthermore, the physically stable formulation showed the active lactone form predominated in HCPT-SMEDDS (> 95%) for 6 months under the accelerated storage condition. Meanwhile, the optimized SMEDDS formulation also significantly improved dissolution rates and membrane permeability of the lactone form of HCPT. Therefore, HCPT-SMEDDS involved designing for the ease of manufacture, and provided a potent oral dosage form for preserving its active lactone form as well as enhancing the dissolution rate.

Current Topics in Esophageal Squamous Cell Carcinoma

Esophageal squamous cell carcinoma (ESCC) is one of the most deadly cancers due to its extremely aggressive nature and poor survival rate. Central to East Asia is one of regions with the highest incidence of ESCC. In these five papers, the international leaders of ESCC in Asia have taken various approaches to ESCC. Lin et al. compared intensity-modulated radiation therapy with three-dimensional stereoscopic radiation therapy with respect to treatment of ESCC. Song et al. demonstrated that (S)-10-Hydroxycamptothecin is useful in the ESCC cell lines as well as in vivo using a patients-derived xenograft tumor model in mice. Chen et al. showed Stromal cell-derived factor-1α expression is an independent prognostic predictor of ESCC. Lin et al. showed that the SUV_LN/SUV_Tumor ratio of PET-CT was associated with ESCC prognosis. Yoon et al. investigated the association between sarcopenia and prognosis in the ESCC patients. All reports are an essential approach to overcoming ESCC.

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

Tumor-targeted drug delivery via chemotherapy is very effective on cancer treatment. For potential anticancer agent such as Camptothecin (CPT), high chemotherapeutic efficacy and accurate tumor targeting are equally crucial. Inspired by special CD44 binding capability from hyaluronic acid (HA), in this study, novel HA-coated CPT nanocrystals were successfully prepared by an antisolvent precipitation method for tumor-targeted delivery of hydrophobic drug CPT. These HA-coated CPT nanocrystals demonstrated high drug loading efficiency, improved aqueous dispersion, prolonged circulation, and enhanced stability resulting from their nanoscaled sizes and hydrophilic HA layer. Moreover, as compared to crude CPT and naked CPT nanocrystals, HA-coated CPT nanocrystals displayed dramatically enhanced in vitro anticancer activity, apoptosis-inducing potency against CD44 overexpressed cancer cells, and lower toxic effect toward normal cells due to pH-responsive drug release behavior and specific HA-CD44 mediated endocytosis. Additionally, HA-coated CPT nanocrystals performed fairly better antimigration activity and biocompatibility. The possible molecular mechanism regarding this novel drug formulation might be linked to intrinsic mitochondria-mediated apoptosis by an increase of Bax to Bcl-2 ratio and upregulation of P53. Consequently, HA-coated CPT nanocrystals are expected to be an effective nanoplatform in drug delivery for cancer therapy.

Advanced modification of drug nanocrystals by using novel fabrication and downstream approaches for tailor-made drug delivery

Drug nanosuspensions/nanocrystals have been recognized as one useful and successful approach for drug delivery. Drug nanocrystals could be further decorated to possess extended functions (such as controlled release) and designed for special in vivo applications (such as drug tracking), which make best use of the advantages of drug nanocrystals. A lot of novel and advanced size reduction methods have been invented recently for special drug deliveries. In addition, some novel downstream processes have been combined with nanosuspensions, which have highly broadened its application areas (such as targeting) besides traditional routes. A large number of recent research publication regarding as nanocrystals focuses on above mentioned aspects, which have widely attracted attention. This review will focus on the recent development of nanocrystals and give an overview of regarding modification of nanocrystal by some new approaches for tailor-made drug delivery.

Lytic peptide-grafted beta-cyclodextrin polymer based nano-scaled drug delivery system with enhanced camptothecin anti-cancer efficacy

The aqueous solubility of drug molecules is closely related to its bioactivity like bioavailability and subsequent therapeutic index, especially in the case of hydrophobic drugs like camptothecin (CPT), a potential broad-spectrum anti-cancer agent. Enhanced anti-cancer activity and selectivity of CPT are equally important. Inspired by host-guest effect and drug combination regimen, we developed a novel tumor lytic peptide incorporated drug delivery system by forming beta-cyclodextrin polymer (BCDp) based inclusion complex in nano-scaled size. In this study, BCDp formed inclusion complex with CPT and then a lytic-type peptide (ZH) was grafted. The resulting combinational formulation of BCDp, CPT and ZH, named as ZH-BCDp-CPT inclusion complex, demonstrated greater solubility resulting from its nano-scaled size, amorphous solid state and inclusion structure. Moreover, ZH facilitated quick internalization of conjugated drug via cell membrane lysis, leading to efficient intracellular drug delivery. This novel drug formulation was featured with prolonged circulation, enhanced anti-cancer efficacy, selectivity, anti-cell migration activity and better biocompatibility in comparison with crude CPT and binary BCDp-CPT inclusion complex, all of which were attributed to a cooperative action between ZH and BCDp-CPT inclusion complex. Our results suggested ZH-BCDp-CPT inclusion complex induced cell apoptosis by up-regulation of Bax and P53 and down-regulation of Bcl-2, primarily involved in the mitochondrial pathways.

Soybean lecithin stabilizes disulfiram nanosuspensions with a high drug-loading content: remarkably improved antitumor efficacy

Disulfiram (DSF) has been considered as "Repurposing drug" in cancer therapy in recent years based on its good antitumor efficacy. DSF is traditionally used as an oral drug in the treatment of alcoholism. To overcome its rapid degradation and instability, DSF nanosuspensions (DSF/SPC-NSps) were prepared using soybean lecithin (SPC) as a stabilizer of high drug-loaded content (44.36 ± 1.09%). Comprehensive characterization of the nanosuspensions was performed, and cell cytotoxicity, in vivo antitumor efficacy and biodistribution were studied. DSF/SPC-NSps, having a spherical appearance with particle size of 155 nm, could remain very stable in different physiological media, and sustained release. The in vitro MTT assay indicated that the cytotoxicity of DSF/SPC-NSps was enhanced remarkably compared to free DSF against the 4T1 cell line. The IC50 value decreased by 11-fold (1.23 vs. 13.93 μg/mL, p < 0.01). DSF/SPC-NSps groups administered via intravenous injections exhibited better antitumor efficacy compared to the commercial paclitaxel injection (PTX injection) and had a dose-dependent effect in vivo. Notably, DSF/SPC-NSps exhibited similar antitumor activity following oral administration as PTX administration via injection into a vein. These results suggest that the prepared nanosuspensions can be used as a stable delivery vehicle for disulfiram, which has potential application in breast cancer chemotherapy.

(S)-10-Hydroxycamptothecin Inhibits Esophageal Squamous Cell Carcinoma Growth In Vitro and In Vivo Via Decreasing Topoisomerase I Enzyme Activity

Topoisomerase (TOP) I plays a major role in the process of supercoiled DNA relaxation, thereby facilitating DNA replication and cell cycle progression. The expression and enzymatic activity of TOP I is positively correlated with tumor progression. Although the anticancer activity of (S)-10-Hydroxycamptothecin (HCPT), a TOP I specific inhibitor, has been reported in various cancers, the effect of HCPT on esophageal cancer is yet to be examined. In this study, we investigate the potential of HCPT to inhibit the growth of ESCC cells in vitro and verify its anti-tumor activity in vivo by using a patient-derived xenograft (PDX) tumor model in mice. Our study revealed the overexpression of TOP I in ESCC cells and treatment with HCPT inhibited TOP I enzymatic activity at 24 h and decreased expression at 48 h and 72 h. HCPT also induced DNA damage by increasing the expression of H2A.X^S139. HCPT significantly decreased the proliferation and anchorage-independent growth of ESCC cells (KYSE410, KYSE510, KYSE30, and KYSE450). Mechanistically, HCPT inhibited the G2/M phase cell cycle transition, decreased the expression of cyclin B1, and elevated p21 expression. In addition, HCPT stimulated ESCC cells apoptosis, which was associated with elevated expression of cleaved PARP, cleaved caspase-3, cleaved caspase-7, Bax, Bim, and inhibition of Bcl-2 expression. HCPT dramatically suppressed PDX tumor growth and decreased the expression of Ki-67 and TOP I and increased the level of cleaved caspase-3 and H2A.X^S139 expression. Taken together, our data suggested that HCPT inhibited ESCC growth, arrested cell cycle progression, and induced apoptosis both in vitro and in vivo via decreasing the expression and activity of TOP I enzyme.

Recent progress in drug delivery

Drug delivery systems (DDS) are defined as methods by which drugs are delivered to desired tissues, organs, cells and subcellular organs for drug release and absorption through a variety of drug carriers. Its usual purpose to improve the pharmacological activities of therapeutic drugs and to overcome problems such as limited solubility, drug aggregation, low bioavailability, poor biodistribution, lack of selectivity, or to reduce the side effects of therapeutic drugs. During 2015-2018, significant progress in the research on drug delivery systems has been achieved along with advances in related fields, such as pharmaceutical sciences, material sciences and biomedical sciences. This review provides a concise overview of current progress in this research area through its focus on the delivery strategies, construction techniques and specific examples. It is a valuable reference for pharmaceutical scientists who want to learn more about the design of drug delivery systems.

Preparation and evaluation of etoposide-loaded lipid-based nanosuspensions for high-dose treatment of lymphoma

Aim: High-dose administration of etoposide (VP16) was limited by its poor aqueous solubility and severe systemic toxicity on lymphoma therapy. Herein, a novel VP16-loaded lipid-based nanosuspensions (VP16-LNS) was developed for improving drug solubility, enhancing antitumor effect and reducing systemic toxicity. Materials & methods: VP16-LNS with soya lecithin and D-α-tocopheryl PEG 1000 succinate (TPGS) as stabilizers were prepared by nanoprecipitation method. Results: VP16-LNS exhibited uniform spherical morphology, small particle size and favorable colloidal stability. The concentration of VP16 in VP16-LNS was high enough (1017.67 μg/ml) for high-dose therapy on lymphoma. Moreover, VP16-LNS displayed long blood circulation time, selective intratumoral accumulation, remarkable antitumor effect and upregulated safety. Conclusion: VP16-LNS would be an efficient nanoformulation for clinical intravenous application against lymphoma.

Folate-targeting annonaceous acetogenins nanosuspensions: significantly enhanced antitumor efficacy in HeLa tumor-bearing mice

Annonaceous acetogenins (ACGs) are one of the most active constituents isolated from Annona species with potent antitumor activity. However, the poor solubility and severe side effect greatly limit their use in clinic. In this study, folic acid (FA) modified annonaceous acetogenins nanosuspensions (FA-PEG-ACGs-NSps) had been successfully prepared using DSPE-PEG-FA and soybean lecithin (SPC) as stabilizers. The resultant FA-PEG-ACGs-NSps had a mean particle size of 119.7 nm, a zeta potential of -23.0 mV and a high drug payload of 49.68%. The obtained ACGs-NSps had a good stability in various physiological media, and showed sustained drug release. Compared to common ACGs nanoparticles (PEG-ACGs-NSps), FA-PEG-ACGs-NSps showed significantly enhanced in vitro cytotoxicity against folate receptor-positive HeLa cell lines (IC50, 0.483 μg/mL vs. 0.915 μg/mL, p < .05), which could be effectively reversed simply by pretreatment of free FA. In vivo experiments demonstrated that FA-PEG-ACGs-NSps brought more drug molecules into tumors and greatly improved the antitumor efficacy (TIR, 76.45% vs. 25.29%, p < .001). Therefore, DSPE-PEG-FA is considered as a proper stabilizer with active targeting effect for ACGs-NSps to reduce toxicity, enlarge the safe dosage range and apply in clinic for the treatment of folate-positive tumors. Therefore, FA-PEG-ACGs-NSps may be a prospective drug delivery system for ACGs to improve their therapeutic window and find application in clinic to treat FR over-expressed tumors.

Bioavailability Enhancement of Poorly Water-Soluble Drugs via Nanocomposites: Formulation⁻Processing Aspects and Challenges

Drug nanoparticles embedded in a dispersant matrix as a secondary phase, i.e., drug-laden nanocomposites, offer a versatile delivery platform for enhancing the dissolution rate and bioavailability of poorly water-soluble drugs. Drug nanoparticles are prepared by top-down, bottom-up, or combinative approaches in the form of nanosuspensions, which are subsequently dried to prepare drug-laden nanocomposites. In this comprehensive review paper, the term &ldquo;nanocomposites&rdquo; is used in a broad context to cover drug nanoparticle-laden intermediate products in the form of powders, cakes, and extrudates, which can be incorporated into final oral solid dosages via standard pharmaceutical unit operations, as well as drug nanoparticle-laden strip films. The objective of this paper is to review studies from 2012⁻2017 in the field of drug-laden nanocomposites. After a brief overview of the various approaches used for preparing drug nanoparticles, the review covers drying processes and dispersant formulations used for the production of drug-laden nanocomposites, as well as various characterization methods including quiescent and agitated redispersion tests. Traditional dispersants such as soluble polymers, surfactants, other water-soluble dispersants, and water-insoluble dispersants, as well as novel dispersants such as wet-milled superdisintegrants, are covered. They exhibit various functionalities such as drug nanoparticle stabilization, mitigation of aggregation, formation of nanocomposite matrix⁻film, wettability enhancement, and matrix erosion/disintegration. Major challenges such as nanoparticle aggregation and poor redispersibility that cause inferior dissolution performance of the drug-laden nanocomposites are highlighted. Literature data are analyzed in terms of usage frequency of various drying processes and dispersant classes. We provide some engineering considerations in comparing drying processes, which could account for some of the diverging trends in academia vs. industrial practice. Overall, this review provides rationale and guidance for drying process selection and robust nanocomposite formulation development, with insights into the roles of various classes of dispersants.