Fine-tuning the activation behaviors of ternary modular cabazitaxel prodrugs for efficient and on-target oral anti-cancer therapy

The disulfide bond plays a crucial role in the design of anti-tumor prodrugs due to its exceptional tumor-specific redox responsiveness. However, premature breaking of disulfide bonds is triggered by small amounts of reducing substances (e.g., ascorbic acid, glutathione, uric acid and tea polyphenols) in the systemic circulation. This may lead to toxicity, particularly in oral prodrugs that require more frequent and high-dose treatments. Fine-tuning the activation kinetics of these prodrugs is a promising prospect for more efficient on-target cancer therapies. In this study, disulfide, steric disulfide, and ester bonds were used to bridge cabazitaxel (CTX) to an intestinal lymph vessel-directed triglyceride (TG) module. Then, synthetic prodrugs were efficiently incorporated into self-nanoemulsifying drug delivery system (corn oil and Maisine CC were used as the oil phase and Cremophor EL as the surfactant). All three prodrugs had excellent gastric stability and intestinal permeability. The oral bioavailability of the disulfide bond-based prodrugs (CTX-(C)S-(C)S-TG and CTX-S-S-TG) was 11.5- and 19.1-fold higher than that of the CTX solution, respectively, demonstrating good oral delivery efficiency. However, the excessive reduction sensitivity of the disulfide bond resulted in lower plasma stability and safety of CTX-S-S-TG than that of CTX-(C)S-(C)S-TG. Moreover, introducing steric hindrance into disulfide bonds could also modulate drug release and cytotoxicity, significantly improving the anti-tumor activity even compared to that of intravenous CTX solution at half dosage while minimizing off-target adverse effects. Our findings provide insights into the design and fine-tuning of different disulfide bond-based linkers, which may help identify oral prodrugs with more potent therapeutic efficacy and safety for cancer therapy.

The endocytosis and intracellular fate of nanomedicines: Implication for rational design

Nanomedicines employ multiple endocytic pathways to enter cells.Their following fate is interesting,but it is not sufficient understood currently.This review introduces the endocytic pathways,presents new technologies to confirm the specific endocytic pathways and discusses factors for pathway selection.In addition,some intriguing implication about nanomedicine design based on endocytosis will also be discussed at the end.This review may provide new thoughts for the design of novel multifunctional nanomedicines.

Small changes in the length of diselenide bond-containing linkages exert great influences on the antitumor activity of docetaxel homodimeric prodrug nanoassemblies

Homodimeric prodrug-based self-assembled nanoparticles,with carrier-free structure and ultrahigh drug loading,is drawing more and more attentions.Homodimeric prodrugs are composed of two drug molecules and a pivotal linkage.The influence of the linkages on the self-assembly,in vivo fate and antitumor activity of homodimeric prodrugs is the focus of research.Herein,three docetaxel(DTX)homodimeric prodrugs are developed using different lengths of diselenide bond-containing linkages.Interestingly,compared with the other two linkages,the longest diselenide bond-containing linkage could facilitate the self-delivery of DTX prodrugs,thus improving the stability,circulation time and tumor targeting of prodrug nanoassemblies.Besides,the extension of linkages reduces the redox-triggered drug release and cytotoxicity of prodrug nanoassemblies in tumor cells.Although the longest diselenide bond-containing prodrug nanoassemblies possessed the lowest cytotoxicity to 4T1 cells,their stable nanostructure maintained intact during circulation and achieve the maximum accumulation of DTX in tumor cells,which finally“turned the table”.Our study illustrates the crucial role of linkages in homodimeric prodrugs,and gives valuable proposal for the development of advanced nano-DDS for cancer treatment.

Application of hot melt extrusion to enhance the dissolution and oral bioavailability of oleanolic acid

The aim of this study was to improve the in vitro dissolution rate and oral bioavailability of oleanolic acid(OA), a water insoluble drug belonging to BCS class IV. Hot melt extrusion(HME) was applied to develop OA amorphous solid dispersions. The characterizations of the optimal formulation were performed by differential scanning calorimetry, X-ray powder diffraction, Fourier transform infrared spectroscopy and in vitro dissolution test.The in vivo pharmacokinetic study was conducted in rats. As a result, OA solid dispersion based on PVP VA 64(OA-PVP) was successfully prepared. In the dissolution medium containing 0.3% SDS, OA-PVP dramatically increased the releasing rate of OA compared with the physical mixture(PM-PVP) and commercial tablet. Furthermore, OA-PVP exhibited higher AUC(P < 0.05) and Cmax(P < 0.05) than PM-PVP and commercial tablet. The superior dissolution property and bioavailability of OA-PVP mainly attributed to the amorphous state of OA in PVP VA64 and the well dispersion caused by thermal melting and shearing. Overall, hot melt extrusion was an efficient strategy to enhance the dissolution rate and oral bioavailability of OA.

Bacteria-Mediated Synergistic Cancer Therapy:Small Microbiome Has a Big Hope

The use of bacteria to specifically migrate to cancerous tissue and elicit an antitumor immune response provides a promising platform against cancer with significantly high potency.With dozens of clinical trials underway,some researchers hold the following views:“humans are nearing the first commercial live bacteria therapeutic.”However,the facultative anaerobe Salmonella typhimurium VNP20009,which is particularly safe and shows anticancer effects in preclinical studies,had failed in a phase I clinical trial due to low tumor regression and undesired dose-dependent side effects.This is almost certain to disappoint people’s inflated expectations,but it is noted that recent stateof-the-art research has turned attention to bacteria-mediated synergistic cancer therapy(BMSCT).In this review,the foundation of bacteria-mediated bio-therapy is outlined.Then,we summarize the potential benefits and challenges of bacterial bio-therapy in combination with different traditional anticancer therapeutic modalities(chemotherapy,photothermal therapy,reactive oxygen and nitrogen species therapy,immunotherapy,or prodrug-activating therapy)in the past 5 years.Next,we discuss multiple administration routes of BMSCT,highlighting potentiated antitumor responses and avoidance of potential side effects.Finally,we envision the opportunities and challenges for BMSCT development,with the purpose of inspiring medicinal scientists to widely utilize the microbiome approach in patient populations.

Iron-doxorubicin prodrug loaded liposome nanogenerator programs multimodal ferroptosis for efficient cancer therapy

Ferroptosis is a new mode of cell death,which can be induced by Fenton reactionmediated lipid peroxidation.However,the insufficient H2O2 and high GSH in tumor cells restrict the efficiency of Fenton reaction-dependent ferroptosis.Herein,a self-supplying lipid peroxide nanoreactor was developed to co-delivery of doxorubicin(DOX),iron and unsaturated lipid for efficient ferroptosis.By leveraging the coordination effect between DOX and Fe3+,trisulfide bond-bridged DOX dimeric prodrug was actively loaded into the core of the unsaturated lipids-rich liposome via iron ion gradient method.First,Fe3+could react with the overexpressed GSH in tumor cells,inducing the GSH depletion and Fe2+generation.Second,the cleavage of trisulfide bond could also consume GSH,and the released DOX induces the generation of H2O2,which would react with the generated Fe2+in step one to induce efficient Fenton reaction-dependent ferroptosis.Third,the formed Fe3+/Fe2+couple could directly catalyze peroxidation of unsaturated lipids to boost Fenton reaction-independent ferroptosis.This iron-prodrug liposome nanoreactor precisely programs multimodal ferroptosis by integrating GSH depletion,ROS generation and lipid peroxidation,providing new sights for efficient cancer therapy.

Investigating the crucial roles of aliphatic tails in disulfide bond-linked docetaxel prodrug nanoassemblies

Disulfide bond-bridging strategy has been extensively utilized to construct tumor specificity-responsive aliphatic prodrug nanoparticles(PNPs) for precise cancer therapy. Yet, there is no research shedding light on the impacts of the saturation and cis-trans configuration of aliphatic tails on the self-assembly capacity of disulfide bond-linked prodrugs and the in vivo delivery fate of PNPs. Herein, five disulfide bond-linked docetaxelfatty acid prodrugs are designed and synthesized by using stearic acid, elaidic acid, oleic acid, linoleic acid and linolenic acid as the aliphatic tails, respectively. Interestingly, the cistrans configuration of aliphatic tails significantly influences the self-assembly features of prodrugs, and elaidic acid-linked prodrug with a trans double bond show poor self-assembly capacity. Although the aliphatic tails have almost no effect on the redox-sensitive drug release and cytotoxicity, different aliphatic tails significantly influence the chemical stability of prodrugs and the colloidal stability of PNPs, thus affecting the in vivo pharmacokinetics, biodistribution and antitumor efficacy of PNPs. Our findings illustrate how aliphatic tails affect the assembly characteristic of disulfide bond-linked aliphatic prodrugs and the in vivo delivery fate of PNPs, and thus provide theoretical basis for future development of disulfide bond-bridged aliphatic prodrugs.

Ratiometric delivery of doxorubicin and berberine by liposome enables superior therapeutic index than Doxil?

Although the appearance of Doxil alleviated the cardiotoxicity of DOX, the progression-free survival of patients was not prolonged compared with traditional medication regimens, and side effects such as hand-foot syndrome has occurred. In order to solve this dilemma, we have designed a novel co-delivery strategy to construct a co-loaded liposome of berberine(BER) and doxorubicin(DOX), which was called Lipo Be Do. The optimal synergistic ratio of the two drugs was screened by cell cytotoxicity experiments in vitro, and the optimal attenuation ratio was further determined by in vivo cardiac H&E staining pathological sections. The optimal combination treatment caused a robust increase in apoptotic cells of 4T1, as compared to drug alone treatment. The prepared co-loaded liposome, Lipo Be Do, had high encapsulation efficiency and good stability. The nanoliposome carrier controlled the biological fate of the drugs and maintained a pre-defined optimal ratio in vivo. The Lipo Be Do significantly inhibited tumor growth in 4T1 murine mammary carcinoma model compared with Doxil(P < 0.05), and completely overcame the myocardial rupture toxicity caused by Doxil in mice. Our co-loaded liposome delivery platform technology provided a new direction for the clinical treatment of triple-negative breast cancer and the safe application of DOX.

Impact of the amount of PEG on prodrug nanoassemblies for efficient cancer therapy

PEGylation has been widely used to improve the pharmacokinetic properties of prodrug self-assembled nanoparticles(prodrug-SANPs).However,the impacts of the amount of PEG on the self-assemble stability,cellular uptake,pharmacokinetics,and antitumor efficacy of prodrug-SANPs are still unknown.Herein,selenoether bond bridged docetaxel dimeric prodrug was synthesized as the model prodrug.Five prodrug-SANPs were designed by using different mass ratios of prodrugs to PEG(W_(prodrug)/W_(DSPE-mPEG2000)=10:0,9:1,8:2,7:3 and 6:4),and defined as Pure drug NPs,9:1NPs,8:2NPs,7:3 NPs and 6:4 NPs,respectively.Interestingly,8:2 NPs formed the most compact nanostructure,thus improving the self-assemble stability and pharmacokinetics behavior.In addition,the difference of these prodrug-SANPs in cellular uptake was investigated,and the influence of PEG on cytotoxicity and antitumor efficacy was also clarified in details.The 8:2 NPs exhibited much better antitumor efficacy than other prodrug-SANPs and even commercial product.Our findings demonstrated the pivotal role of the amount of PEG on prodrug-SANPs.

Naringenin nanocrystals for improving antirheumatoid arthritis activity

Naringenin(NAR)is recognized for its anti-inflammatory activity.However,the clinical application of NAR is limited by low bioavailability,which is attributed to its poor aqueous solubility.In this study,we aimed to improve the therapeutic efficacy of NAR by formulating it into nanocrystals(NCs)via wet milling.The obtained NARNCs exhibited superior dissolution behaviors,increased cellular uptake,and enhanced transcellular diffusion relative to those of bulk NAR.Oral administration of NARNCs also significantly improved bioavailability in rats.In addition,the NARNCs effectively improved rheumatoid arthritis treatment in collagen-induced arthritic rats by reducing inflammatory cell infiltration and synovial damage.These results indicate that NARNCs provides a promising strategy for rheumatoid arthritis treatment.

Exploring the relationship of hyaluronic acid molecular weight and active targeting efficiency for designing hyaluronic acid-modified nanoparticles

Although it is reported that the targeting ability of hyaluronic acid(HA)-based nanoparticles(NPs) is molecular weight(MW) dependent,the influence of HA MW on targeting efficiency of HA-functionalized NPs and the underlying mechanism remain elusive. In this study,we constituted three HA-functionalized Dox-loaded NPs(Dox/HCVs) different HA MWs(7,63,and 102 k Da) and attempted to illustrate the effects of HA MW on the targeting efficiency.The three Dox/HCVs had similar physiochemical and pharmaceutical characteristics,but showed different affinity to CD44 receptor. Furthermore,Dox/HCV-63 exerted the best targeting effect and the highest cytotoxicity compared with Dox/HCV-7 and Dox/HCV-102. It was interesting to found that both the HA-CD44 binding affinity and induced CD44 clustering by HA-based NPs were HA MW-dependent,the two of which determine the apparent targeting efficacy of Dox/HCV NPs in the conflicting directions. Those results laid a good foundation for rationally designing HA-based NPs in cancer therapy.

Development and validation of a UPLC–MS/MS assay for the determination of gemcitabine and its L-carnitine ester derivative in rat plasma and its application in oral pharmacokinetics

A simple and rapid UPLC–MS/MS method to simultaneously determine gemcitabine and its L-carnitine ester derivative(2’-deoxy-2’, 2’-difluoro-N-((4-amino-4-oxobutanoyl) oxy)-4-(trimethyl amm-onio) butanoate-cytidine, JDR) in rat plasma was developed and validated.The conventional plasma sample preparation method of nucleoside analogues is solidphase extraction(SPE) which is time-consuming and cost-expensive. In this study, gradient elution with small particles size solid phase was applied to effectively separate gemcitabine and JDR, and protein precipitation pretreatment was adopted to remove plasma protein and extract the analytes with high recovery(>81%). Method validation was performed as per the FDA guidelines, and the standard curves were found to be linear in the range of 5–4000 ng/ml for JDR and 4–4000 ng/ml for gemcitabine, respectively. The lower limit of quantitation(LLOQ)of gemcitabine and JDR was 4 and 5 ng/ml, respectively. The intra-day and inter-day precision and accuracy results were within the acceptable limits. Finally, the developed method was successfully applied to investigate the pharmacokinetic studies of JDR and gemcitabine after oral administration to rats.

The effect of cephalexin in influencing the pharmacokinetics of a novel drug–5’-valyl-cytarabine hydrochloride

The aim of this study is to investigate the pharmacokinetics of 5′-valyl-cytarabine hydrochloride(OPC) when co-administered with cephalexin, which are both the substrates of PepT 1.The drugs were administered orally by gavage. Blood samples were collected from the orbital plexus of the rats after oral administration of drug solutions. A new high-performance liquid chromatographic method was validated and used for determination of the two drugs. Pharmacokinetic parameters were calculated using DAS 2.1.1 software with noncompartmental analysis. After oral administration of OPC and co-administration of OPC and cephalexin,there were significant differences in the main pharmacokinetic parameters. The main pharmacokinetic parameters for the OPC group and the co-administrative group were as follows:AUC0-10(18,168.7 ± 2561.4) ng·h/ml and(13,448.5 ± 2544.73) ng·h/ml, AUC0-∞(18,683.1 ± 3066.5)ng·h/ml and(13,721.1 ± 2683.0) ng·h/ml, Cmax(6654.8 ± 481.3) ng/ml and(4765.1 ± 928.9) ng/ml, respectively. The results showed that the bioavailability of OPC could be reduced when co-administered with cephalexin, suggesting that the efficacy of a novel drug might be reduced when it came to combination use of β-lactam antibiotics.

A computer-aided chem-photodynamic drugs self-delivery system for synergistically enhanced cancer therapy

The therapeutic strategy that gives consideration to the combination of photodynamic therapy and chemotherapy,has emerged as a potential development of effective anti-cancer medicine.Nevertheless,co-delivery of photosensitizers(PSs)and chemotherapeutic drugs in traditional carriers still remains great limitations due to low drug loadings and poor biocompatibility.Herein,we have utilized a computer-aided strategy to achieve a desired carrier-free self-delivery of pyropheophorbide a(PPa,a common PS)and podophyllotoxin(PPT,a classical chemotherapeutic drug)for synergistic cancer therapy.First,the computational simulation method identified the similar molecular sizes and rigid molecular structures between two drugs molecules.Based on the molecular docking,the intermolecular interactions were found to includeπ-πstackings,hydrophobic interactions and hydrogen bonds.Next,both drugs could co-assemble into nanoparticles(NPs)via one-step nanoprecipitation method.The various spectral experiments(UV,IR and FL)were conducted to evaluate the formation mechanism of spherical NPs.Moreover,in vitro and in vivo experiments systematically demonstrated that PPT/PPa NPs not only showed better cellular uptake efficiency,stronger cytotoxicity and higher accumulation in tumor sites,but also exhibited synergistic antitumor effect in female BALB/C bearing-4T1 tumor mice.Such a computer-aided design strategy of chem-photodynamic drugs self-delivery systems pave the way for efficient synergistic cancer therapy.

Thin-film hydration preparation method and stability test of DOX-loaded disulfide-linked polyethylene glycol 5000-lysine-di-tocopherol succinate nanomicelles

A novel redox-responsive PEG-sheddable copolymer of disulfide-linked polyethylene glycol 5000-lysine-di-tocopherol succinate(P_(5k)SSLV)was designed and synthesized.Thin-film hydration method was used to prepare DOX-loaded P_(5k)SSLV nanomicelle.To optimize the preparation technology,we investigate the effects of dosage,type of organic solvent,hydration temperature and time,and cryoprotectant on drug-loading content,encapsulation efficiency,particle size,and zeta potential.The mean particle size and zeta potential were determined by Zetasizer.The morphology of the P_(5k)SSLV-DOX nanomicelles was visualized by transmission electron microscopy.The drug-loading content and encapsulation efficiency of P_(5k)SSLV-DOX nanomicelle were investigated by UV.The drug-loading content,encapsulation efficiency,particle size,and zeta potential of the final optimized nanomicelles were 4.58%,97.20%,30.21 nm and -0.84 mV,respectively.In addition,the stability of nanomicelles was investigated,which included dilution stability and storage stability.The results showed that P_(5k)SSLV-DOX nanomicelle had good dilution stability and storage stability at 4℃.The preparation method of P_(5k)SSLV-DOX nanomicelle with thinfilm hydration method was practical and simple,which was valuable to be further studied.

Effect of raw material variability of glipizide on the in vitro dissolution rate and in vivo bioavailability performance: The importance of particle size

The objective of this study was to understand the impact of active pharmaceutical ingredients(API) particle size on a re-developed generic product of glipizide and to improve its formulation so that it exhibits bioequivalent to that of the reference listed drug(RLD). Two commercial batches of APIs(API-1 and API-2) with the same polymorphism and one batch of home-made APIs(API-3) with super-small particle size were used in the present study.The in vitro dissolution profiles of the tested formulations were compared with the RLD in a series of dissolution media. Then, the impact of particle size on in vivo absorption was evaluated in Beagle dogs. Compared with the RLD, formulation A with larger API size showed slower dissolution in p H 6.0 and 7.4 medium, resulting bioinequivalent with the RLD. Conversely, formulation B with smaller API size demonstrated similar in vitro dissolution profiles with the RLD and thus exhibited bioequivalent in the present study. Furthermore, formulation C with super small particle size still exhibited identical oral absorption although rapid dissolution was observed in the tested condition. Herein, it indicated that 2–5 μm might be defined as the "inert size range" of glipizide for ensuring the bioequivalence with the RLD. The results in the present study might help to obtain a better understanding of the variability in raw materials for oral absorption, develop a bioequivalent product and thus post-market quality control.

Piperacillin enhances the inhibitory effect of tazobactam on β-lactamase through inhibition of organic anion transporter 1/3 in rats

To assess the mechanism of the pharmacokinetic interaction between piperacillin and tazobactam,renal excretion and pharmacokinetic studies of piperacillin/tazobactam were investigated in normal and bacteremia rats.A bacteremia model was established to investigate the pharmacokinetic properties of piperacillin and tazobactam under different conditions.Renal slices were taken to examine the uptake of piperacillin and tazobactam.Pharmacokinetic studies ofβ-lactamase in rats were performed to study the contribution of rOat1/3 to the inhibition of tazobactam onβ-lactamase.The AUC(from 2.93±0.58 to 6.52±1.44 mg·min/ml)and the plasma clearance(CL P)(from 2.41±1.20 to 0.961±0.212 ml/min/kg)of tazobactam were both altered after the intravenous coadministration of piperacillin and tazobactam in the bacteremia rats.The renal clearance(CL R)of tazobactam decreased from 1.30±0.50 to 0.361±0.043 ml/min/kg.In summary,there was a beneficial interaction between piperacillin and tazobactam mediated by rOat1 and rOat3.Piperacillin enhances the inhibitory effect of tazobactam onβ-lactamase through the inhibition of rOat1 and rOat3 in rats.The contribution rate of rOat1/3 for the synergistic effect was 20%when the two drugs were coadministered.

The application of open disk-like structures as model membrane and drug carriers

The objective of this review is to outline the application of bicelles(or called bilayer micelles)and bilayer nanodisks in pharmaceutics,pharmaceutical analysis and biochemistry.The application of open disk-like structures as model membrane and drug carrier has been described.The exploration of many reports in different fields suggested that these open disk-like structures have great potential in studying interactions between drug-membrane and structure/function studies of membrane-bound proteins.Furthermore,they could be applied as promising carriers for in vivo delivery of drugs,protein and peptide.

The effect of lengths of branched-chain fatty alcohols on the efficacy and safety of docetaxel-prodrug nanoassemblies

The self-assembly prodrugs are usually consisted of drug modules,activation modules,and assembly modules.Keeping the balance between efficacy and safety by selecting suitable modules remains a challenge for developing prodrug nanoassemblies.This study designed four docetaxel(DTX)prodrugs using disulfide bonds as activation modules and different lengths of branched-chain fatty alcohols as assembly modules(C_(16),C_(18),C_(20),and C_(24)).The lengths of the assembly modules determined the self-assembly ability of prodrugs and affected the activation modules’sensitivity.The extension of the carbon chains improved the prodrugs’self-assembly ability and pharmacokinetic behavior while reducing the cytotoxicity and increased cumulative toxicity.The use of C_(20) can balance efficacy and safety.These results provide a great reference for the rational design of prodrug nanoassemblies.

Advanced nanotherapeutics inspired by the abnormal microenvironment of leukemia

During the development of leukemia,the overgrowth of leukemia cells in the bone marrow transforms the normal hematopoietic microenvironment into the leukemia microenvironment which favors its growth and inhibits normal hematopoietic stem cells.The leukemia microenvironment exhibits abnormalities in redox substances,metabolism,immune response,mesenchymal cells,extracellular matrix,stromal cells,hypoxia,and more.These factors collectively provide a shelter for the malignant proliferation of leukemia cells.Recently,as the understanding of the leukemia microenvironment deepens,targeting or remodeling the abnormal leukemia microenvironment is becoming an effective strategy for leukemia treatment.Nanomedicine technology can effectively change pharmacokinetic profiles,thus demonstrating many advantages in modulating the leukemia microenvironment and improving therapeutic selectivity.In this review,we outline the characteristics of abnormal leukemia bone marrow microenvironment,focusing on the abnormal changes in the redox,metabolic and immune microenvironment.We also summarize emerging nanotechnology strategies in remodeling or targeting the aforementioned abnormal microenvironment.In addition,the unique advantages and bright prospects of nanotechnology in remodeling and targeting the leukemia microenvironment are discussed.