Identification of diterpenoids from Salvia castanea Diels f. tomentosa Stib and their antitumor activities.

Four new diterpenoid tropolones, salvirrddones A-D (1-4), and four new icetexanes, salvirrddices A-D (9-12), along with thirteen new 11,12-seco-norabietane diterpenoids, salvirrddnor A-M (14-24, 31, 32) and sixteen known compounds (5-8, 13, 25-30, 33-37), were isolated from the roots and rhizomes of Salvia castanea Diels f. tomentosa Stib. Their structures were elucidated by comprehensive spectroscopic analyses, quantum chemical calculations, and X-ray crystallography. Structurally, compounds 1-8 represent a class of rare natural products featuring a unique cyclohepta-2,4,6-trienone moiety with diterpenoid skeletons. Bioassays showed that only diterpenoid tropolones 3, 5, 6, and 7 exhibited significant activity against several human cancer cell lines with IC50 values ranging from 3.01 to 11.63 µM. Additionally, 3 was shown to inhibit Hep3B cell proliferation, block the G0/G1 phase of the cell cycle, induce mitochondrial dysfunction and oxidative stress, promote apoptosis, as well as inhibit migration and invasion in vitro. Meanwhile, 3 demonstrated anti-proliferative, pro-apoptotic, and migration-inhibitory effects in the Hep3B xenograft zebrafish model in vivo. Network pharmacological analysis and molecular docking results suggested that 3 may treat hepatocellular carcinoma (HCC) through the PI3K-Akt signaling pathway, as well as by binding PARP1 and CDK2 targets. Overall, the present results extremely expand the repertoire of diterpenoids from natural products and may provide a novel chemical scaffold for the discovery of new antitumor drugs.

Errate: Role of Ca²âº in Inhibiting Ischemia-Induced Apoptosis of Parathyroid Gland Cells in New Zealand White Rabbits.

In Figure 1A, the images of CG 24h group and Sham 72h group are duplicated, where the picture of Sham 72h group is correct, now the authors have corrected the picture of CG 24h group. In Figure 2A, the images of CG 72h and CSG 72h groups are duplicated, the images of CG 168h and CSG 168h groups are duplicated，where the pictures of CG 168h and CSG 72h groups are correct, now the authors have corrected the pictures of CG 72h and CSG 168h groups. In Figure 3B, the images of CG 24h group and CSG 72h group are duplicated, where the picture of CSG 72h group is correct, now the authors have corrected the picture of CG 24h group. Reference: Wei-han Cao, Yan-jun Su, Nian-qiu Liu, Ying Peng, Chang Diao, Ruo-chuan Cheng: Role of Ca²âº in Inhibiting Ischemia-Induced Apoptosis of Parathyroid Gland Cells in New Zealand White Rabbits. Med Sci Monit, 2020; 26: e920546. DOI: 10.12659/MSM.920546.

Role of Ca²âº in Inhibiting Ischemia-Induced Apoptosis of Parathyroid Gland Cells in New Zealand White Rabbits.

BACKGROUND Hypoparathyroidism is a common complication after thyroidectomy. Calcium supplementation can relieve these symptoms, but it is not clear whether it can protect the parathyroid glands. This study aimed to verify whether Ca²âº inhibits the apoptosis of parathyroid cells following ischemic injury. MATERIAL AND METHODS A rabbit model of parathyroid gland ischemic injury was established. The blood calcium concentrations were measured by colorimetry. The parathyroid hormone (PTH) levels were measured by enzyme-linked immunosorbent assay (ELISA). The parathyroid tissues were observed by hematoxylin and eosin (H&E) staining and the TdT-mediated dUTP nick-end labeling (TUNEL) assay. Western blotting was used to quantify the levels of the following proteins: caspase-3 and p38 MAP Kinase (p38 MAPK). RESULTS This study demonstrates that apoptosis can be a part of the pathological changes associated with parathyroid ischemic injury. Calcium supplementation inhibited the apoptosis of parathyroid cells following ischemic injury. There were no significant differences among the serum calcium levels from the Sham operation (Sham), the Control group (CG), or the Calcium supplementation group (CSG) after 24 h, 72 h, and 168 h of treatment. PTH levels in the CG were significantly higher than in the CSG at 24 h and 72 h after treatments. The apoptosis rate of parathyroid cells from rabbits in the CSG was significantly lower than that of those from rabbits in the CG at 24 h and 72 h after the treatment. Calcium supplementation inhibited p38 MAPK and caspase-3 expression. CONCLUSIONS This study demonstrates that calcium supplementation inhibited the apoptosis of parathyroid cells following ischemic injury.

On the inherent properties of Soluplus and its application in ibuprofen solid dispersions generated by microwave-quench cooling technology.

Polyvinyl caprolactam-polyvinyl acetate-polyethylene glycol graft copolymer, or Soluplus®, is a relatively new copolymer and a promising carrier of amorphous solid dispersions. Knowledge on the inherent properties of Soluplus® (e.g. cloud points, critical micelle concentrations, and viscosity) in different conditions is relatively inadequate, and the application characteristics of Soluplus®-based solid dispersions made by microwave methods still need to be clarified. In the present investigation, the inherent properties of a Soluplus® carrier, including cloud points, critical micelle concentrations, and viscosity, were explored in different media and in altered conditions. Ibuprofen, a BCS class II non-steroidal anti-inflammatory drug, was selected to develop Soluplus®-based amorphous solid dispersions using the microwave-quench cooling (MQC) method. Scanning electronic microscopy (SEM), differential scanning calorimetry (DSC), powder X-ray diffraction (PXRD), Raman spectroscopy (RS), and Fourier transform infrared spectroscopy (FT-IR) were adopted to analyze amorphous properties and molecular interactions in ibuprofen/Soluplus® amorphous solid dispersions generated by MQC. Dissolution, dissolution extension, phase solubility, equilibrium solubility, and supersaturated crystallization inhibiting experiments were performed to elucidate the effects of Soluplus® on ibuprofen in solid dispersions. This research provides valuable information on the inherent properties of Soluplus® and presents a basic understanding of Soluplus® as a carrier of amorphous solid dispersions.

The Influence of Cellulosic Polymer's Variables on Dissolution/Solubility of Amorphous Felodipine and Crystallization Inhibition from a Supersaturated State.

The collective impact of cellulosic polymers on the dissolution, solubility, and crystallization inhibition of amorphous active pharmaceutical ingredients (APIs) is still far from being adequately understood. The goal of this research was to explore the influence of cellulosic polymers and incubation conditions on enhancement of solubility and dissolution of amorphous felodipine, while inhibiting crystallization of the drug from a supersaturated state. Variables, including cellulosic polymer type, amount, ionic strength, and viscosity, were evaluated for effects on API dissolution/solubility and crystallization processes. Water-soluble cellulosic polymers, including HPMC E15, HPMC E5, HPMC K100-LV, L-HPC, and MC, were studied. All cellulosic polymers could extend API dissolution and solubility to various extents by delaying crystallization and prolonging supersaturation duration, with their effectiveness ranked from greatest to least as HPMC E15 > HPMC E5 > HPMC K100-LV > L-HPC > MC. Decreased polymer amount, lower ionic strength, or higher polymer viscosity tended to decrease dissolution/solubility and promote crystal growth to accelerate crystallization. HPMC E15 achieved greatest extended API dissolution and maintenance of supersaturation from a supersaturated state; this polymer thus had the greatest potential for maintaining sustainable API absorption within biologically relevant time frames.

[Rules and characteristics of crystallization inhibition of cellulose polymers against drugs in supersaturated states].

This study aims to explore the characteristics of crystallization inhibition by cellulose polymers at the supersaturated states of drugs. The study was performed by simulating supersaturated process and preparing supersaturated drug solid, and was carried out by measuring the content of drugs at different time points using dissolution apparatus. The types, amounts, ionic intensity and viscosity of cellulose polymers were examined to assess the crystallization inhibition effect on BCS II class drug indomethacin. HPMC E15 exhibited the strongest crystallization inhibition effect. The more added, more obvious crystallization suppression was observed against indomethacin. The decrease in viscosity and increase in ionic intensity led to an enhanced inhibition. The research provides a scientific guide for the crystallization inhibition of supersaturated drug by cellulose polymers.

Deoxycholic acid-grafted PEGylated chitosan micelles for the delivery of mitomycin C.

Mitomycin C (MTC) was incorporated to a micelle system preparing from a polymer named deoxycholic acid chitosan-grafted poly(ethylene glycol) methyl ether (mPEG-CS-DA). mPEG-CS-DA was synthesized and characterized by (1)H nuclear magnetic resonance ((1)H-NMR) and Fourier transform infrared spectroscopy. mPEG-CS-DA formed a core-shell micellar structure with a critical micelle concentration of 6.57 µg/mL. The mPEG-CS-DA micelles were spherical with a hydrodynamic diameter of about 231 nm. After poly(ethylene glycol)ylation of deoxycholic acid chitosan (CS-DA), the encapsulation efficiency and drug loading efficiency increased from 50.62% to 56.42% and from 20.51% to 24.13%, respectively. The mPEG-CS-DA micelles possessed a higher drug release rate than the CS-DA micelles. For pharmacokinetics, the area under the curve (AUC) of the mPEG-CS-DA micelles was 1.5 times higher than that of MTC injection, and these micelles can enhance the bioavailability of MTC. mPEG-CS-DA micelles reduced the distribution of MTC in almost all normal tissues and had the potential to improve the kidney toxicity caused by MTC injection.

Effect of polymers and media type on extending the dissolution of amorphous pioglitazone and inhibiting the recrystallization from a supersaturated state.

Amorphous forms of crystalline drug are widely utilized for bioavailability enhancement of low solubility drugs in the pharmaceutical industry. Polymers have been found to be effective crystallization inhibitors for amorphous forms in solid states during storage or in liquid states during dissolution process. The dissolution and crystallization behaviors of these amorphous forms in the presence or absence of polymers are still far from adequately understood especially in different dissolution environments. The objective of this study was to investigate the effects of polymers and media type on extending the dissolution of amorphous pioglitazone and inhibiting the recrystallization from a supersaturated state. Polyvinylpyrrolidone K30 (PVPK30), polyvinylpyrrolidone K90 (PVPK90), polyethylene glycol 6000 (PEG6000), polyethylene-polypropylene glycol 188 (F-68), hydroxypropylmethylcellulose (HPMC) and beta-cyclodextrin (ß-CD) were employed to understand these behaviors changes because these polymers were used widely. Three solutions including neutral water and phosphate buffer solutions (PBS, pH6.8 and pH7.4) were adopted as dissolution media to determine the behaviors changes comprehensively. In the presence of polymers, dissolution and solubility were extended to different degrees in three media. Polymers can delay the crystallization routes dependently of the medium type. Buffer salts in media reduced the dissolution and accelerated the crystallization process. Crystallization inhibition of these polymers was strongly dependent on the type and pH of media. HPMC displayed the strongest crystallization inhibition effects, resulting in the greatest degree of maintaining a supersaturated state that can sustain most effectively for biologically relevant timeframes.

[Application of microwave irradiation technology to the field of pharmaceutics].

Microwaves can be directly transformed into heat inside materials because of their ability of penetrating into any substance. The degree that materials are heated depends on their dielectric properties. Materials with high dielectric loss are more easily to reach a resonant state by microwaves field, then microwaves can be absorbed efficiently. Microwave irradiation technique with the unique heating mechanisms could induce drug-polymer interaction and change the properties of dissolution. Many benefits such as improving product quality, increasing energy efficiency and reducing times can be obtained by microwaves. This paper summarized characteristics of the microwave irradiation technique, new preparation techniques and formulation process in pharmaceutical industry by microwave irradiation technology. The microwave technology provides a new clue for heating and drying in the field of pharmaceutics.

Multibarrier-penetrating drug delivery systems for deep tumor therapy based on synergistic penetration strategy.

Nanotherapies, valued for their high efficacy and low toxicity, frequently serve as antitumor treatments, but do not readily penetrate deep into tumor tissues and cells. Here we developed an improved tumor-penetrating peptide (TPP)-based drug delivery system. Briefly, the established TPP iNGR was modified to generate a linear NGR peptide capable of transporting nanotherapeutic drugs into tumors through a CendR pathway-dependent, neuropilin-1 receptor-mediated process. Although TPPs have been reported to reach intended tumor targets, they often fail to penetrate cell membranes to deliver tumoricidal drugs to intracellular targets. We addressed this issue by harnessing cell penetrating peptide technology to develop a liposome-based multibarrier-penetrating delivery system (mbPDS) with improved synergistic drug penetration into deep tumor tissues and cells. The system incorporated doxorubicin-loaded liposomes coated with nona-arginine (R9) CPP and cyclic iNGR (CRNGRGPDC) molecules, yielding Lip-mbPDS. Lip-mbPDS tumor-targeting, tumor cell/tissue-penetrating and antitumor capabilities were assessed using CD13-positive human fibrosarcoma-derived cell (HT1080)-based in vitro and in vivo tumor models. Lip-mbPDS evaluation included three-dimensional layer-by-layer confocal laser scanning microscopy, cell internalization/toxicity assays, three-dimensional tumor spheroid-based penetration assays and antitumor efficacy assays conducted in an animal model. Lip-mbPDS provided enhanced synergistic drug penetration of multiple biointerfaces for potentially deep tumor therapeutic outcomes.

[The development of co-amorphous drug systems].

Converting two poorly water-soluble crystalline drugs to co-amorphous drug systems by ball milling, quench-cooling, or cryo-milling method can improve stability of the drug, enhance dissolution rates, and reduce adverse reactions of the single drug. Co-amorphous system has been used to solve problems of co-administration of medicines. Formation and intermolecular interactions of co-amorphous drug systems may be verified by differential scanning calorimetry (DSC), X-ray powder diffraction (XRPD), Raman spectroscopy (RS) and Fourier transform infrared spectroscopy (FT-IR). Stability of co-amorphous drug systems is influenced by their glass transition temperature (Tg) and intermolecular interactions. The theoretical Tg values and the interaction parameter x are calculated by Gordon-Taylor equation and the Flory-Huggins equation, respectively. Thus, co-amorphous drug systems are analyzed theoretically at molecular level. Co-amorphous drug systems provide a new sight for the co-administration of medicines.

Influence of encapsulation variables on formation of leuprolide-loaded PLGA microspheres.

Emulsion-based solvent evaporation microencapsulation methods for producing PLGA microspheres are complex often leading to empirical optimization. This study aimed to develop a more detailed understanding of the effects of process variables on the complex emulsification processes during encapsulation of leuprolide in PLGA microspheres using a high-shear rotor-stator mixer. Following extensive analysis of previously developed formulation conditions that yield microspheres of equivalent composition to the commercial 1-month Lupron Depot, multiple variables during the formation of primary and secondary emulsion were investigated with the aid of dimensional analysis, including: rotor speed (ω) and time (t), dispersed phase fraction (Φ) and continuous phase viscosity (µc). The dimensionless Sauter mean diameter (d3,2) of primary emulsion was observed to be proportional to the product of several key dimensionless groups (Φ1,We,Re,ω1t1) raised to the appropriate power indices. A new dimensionless group (Θ ) (surface energy/energy input) was used to rationalize insertion of a proportionate time dependence in the scaling of the d3,2. The dimensionless d3,2 of secondary emulsion was found proportional to the product of three dimensionless groups ( [Formula: see text] ) raised to the appropriate power indices. The increased viscosity of the primary emulsion, decreased secondary water phase volume and reduced second homogenization time each elevated encapsulation efficiency of peptide by reducing drug leakage to the outer water phase. These results could be useful for dimensional analysis and improving manufacturing of PLGA microspheres by the solvent evaporation method.

Two new sesquiterpenoids with glycosides from the leaves and stems of Schisandra chinensis (Turcz.) Baill.

Two previously undescribed glycosidic bisnorsesquiterpenoids A - B (1 - 2), together with two known compounds (3 - 4), were isolated from the leaves and stems of Schisandra chinensis. Their structures were elucidated by extensive spectroscopic data (1D, 2D NMR, and HRESIMS). The anti-inflammatory activity, ABTS+ radical scavenging activity, and DPPH radical scavenging activity of compounds 1 - 4 were tested. However, all of these compounds showed only weak anti-inflammatory or antioxidant effects.

Mechanistic evaluation of the initial burst release of leuprolide from spray-dried PLGA microspheres.

Spray-dried poly(lactic-co-glycolic acid) (PLGA) peptide-loaded microspheres have demonstrated similar long-term in vitro release kinetics compared to those produced by the solvent evaporation method and commercial products. However, the difficult-to-control initial burst release over the first 24 h after administration presents an obstacle to product development and establishing bioequivalence. Currently, detailed information about underlying mechanisms of the initial burst release from microspheres is limited. We investigated the mechanism and extent of initial burst release using 16 previously developed spray-dried microsphere formulations of the hormone drug, leuprolide acetate, with similar composition to the commercial 1-month Lupron Depot® (LD). The burst release kinetics was measured with a previously validated continuous monitoring system as well as traditional sample-and-separate methods. The changes in pore structure and polymer permeability were investigated by SEM imaging and the uptake of a bodipy-dextran probe. In vitro results were compared to pharmacokinetics in rats over the same interval. High-burst, spray-dried microspheres were differentiated in the well-mixed continuous monitoring system but reached an upper limit when measured by the sample-and-separate method. Pore-like occlusions observed by confocal microscopy in some formulations indicated that particle swelling may have contributed to probe diffusion through the polymer phase and showed the extensive internal pore structure of spray-dried particles. Continuous monitoring revealed a rapid primary (1°) phase followed by a constant-rate secondary (2°) release phase, which comprised ∼80% and 20% of the 24-hr release, respectively. The ratio of 1° phase duration (t1°) and the characteristic probe diffusion time (τ) was highly correlated to 1° phase release for spray dried particles. Of the four spray-dried formulations administered in vivo, three spray-dried microspheres with similar polymer density showed nearly ideal linear correlation between in vivo absorption and well-mixed in vitro release kinetics over the first 24 h. By contrast, the more structurally dense LD and a more-dense in-house formulation showed a slight lag phase in vivo relative to in vitro. Furthermore, in vitro dimensionless times (tburst/τ) were highly correlated with pharmacokinetic parameters for spray-dried microspheres but not for LD. While the correlation of increases in effective probe diffusion and 1° phase release strongly suggests diffusion through the polymer matrix as a major release mechanism both in vitro and in vivo, a fixed lower limit for this release fraction implies an alternative release mechanism. Overall, continuous monitoring release and probe diffusion appears to have potential in differentiating between leuprolide formulations and establishing relationships between in vitro release and in vivo absorption during the initial burst period.

Cyclin genes as potential novel prognostic biomarkers and therapeutic targets in breast cancer.

Cell cycle progression and cell proliferation are tightly controlled processes physiologically; however, in cancerous cells, uncontrolled cell proliferation may be attributed to abnormal expression of the cyclin genes. Therefore, analysis of the expression of the cyclin genes may result in the discovery of biomarkers that can be used to predict a prognosis and help to evaluate the therapeutic efficacy more accurately in several types of cancer, including breast cancer. In this study, 15 subtypes of the cyclin genes in breast cancer from public databases were selected using bioinformatics analysis, the correlation between their transcriptional expression levels and survival rates were analyzed, and the results were further confirmed using reverse transcription-quantitative PCR in vitro in various breast cancer cell lines. The expression of the majority of the cyclin genes in SK-BR-3, a HER2 overexpressing breast cancer cell line, was lower than that in MCF-10A cells. CCNC mRNA expression was higher and CCNH mRNA expression was lower in tumor and tumor-adjacent tissues compared with that in normal tissues; however, CCNC expression was lower and CCNH expression was higher in breast cancer cell lines compared with that in MCF-10A cells. The expression of the 13 other cyclin genes in breast cancer cell lines was generally consistent with the data from the bioinformatics analyses of breast cancer tissue samples, tumor-adjacent tissues, and normal tissues. Low expression of CCNA2, CCNB1/2, CCNC, CCND1, CCNE1/2 and CCNF, and high expression of CCNA1, CCNB3, CCND2/3, CCNG1/2 and CCNH genes was correlated with a higher survival rate for breast cancer patients (P<0.05). In conclusion, CCNA2, CCNB1/2, CCND1/2 and CCNE1/2 may serve as relatively mature and accurate biomarkers, and CCNG1/2 may be used to evaluate the prognosis and therapeutic efficacy of hormone receptor-positive breast cancer. Furthermore, CCNA1, CCNB3, CCNC, CCND3, CCNF and CCNH may serve as promising targets for the management of breast cancer.

"Felodipine-indomethacin" co-amorphous supersaturating drug delivery systems: "Spring-parachute" process, stability, in vivo bioavailability, and underlying molecular mechanisms.

Amorphous solid dispersions (ASD) are one of most commonly used supersaturating drug delivery systems (SDDS) to formulate insoluble active pharmaceutical ingredients. However, the development of polymer-guided stabilization of ASD systems faces many obstacles. To overcome these shortcomings, co-amorphous supersaturable formulations have emerged as an alternative formulation strategy for poorly soluble compounds. Noteworthily, current researches around co-amorphous system (CAS) are mostly focused on preparation and characterization of these systems, but more detailed investigations of their supersaturation ("spring-parachute" process), stability, in vivo bioavailability and molecular mechanisms are inadequate and need to be clarified. In present study, we chose pharmacological relevant BCS II drugs to fabricate and characterize "felodipine-indomethacin" CAS. To enrich the current inadequate but key knowledge on CAS studies, we carried out following highlighted investigations including dissolution/solubility, semi-continuous "spring-parachute" process, long-term stability profile of amorphous state, in vivo bioavailability and underlying molecular mechanisms (molecular interaction, molecular miscibility and crystallization inhibition). Generally, the research provides some key information in the field of current "drug-drug" CAS supersaturable formulations.

Microencapsulation of luteinizing hormone-releasing hormone agonist in poly (lactic-co-glycolic acid) microspheres by spray-drying.

A spray drying technique was developed to prepare injectable and biodegradable poly(lactic-co-glycolic acid) (PLGA) microspheres encapsulating a model luteinizing hormone-releasing hormone agonist (LHRHa)-based peptide, leuprolide. Various spray drying parameters were evaluated to prepare 1-month controlled release formulations with a similar composition to the commercial Lupron Depot® (LD). A single water-in-oil emulsion of aqueous leuprolide/gelatin solution in PLGA 75/25 acid capped (13 kDa Mw) dissolved in methylene chloride (DCM) was spray-dried before washing the microspheres in cold ddH2O and freeze-drying. The spray-drying microencapsulation was characterized by: particle size/distribution (span), morphology, drug/gelatin loading, encapsulation efficiency, and residual DCM and water content. Long-term release was tested over 9 weeks in PBS + 0.02% Tween 80 + 0.02% sodium azide pH 7.4 (PBST) at 37 °C. Several physical-chemical parameters were monitored simultaneously for selected formulations, including: water uptake, mass loss, dry and hydrated glass transition temperature, to help understand the related long-term release profiles and explore the underlying controlled-release mechanisms. Compared with the commercial LD microspheres, some of the in-house spray-dried microspheres presented highly similar or even improved long-term release profiles, providing viable long-acting release (LAR) alternatives to the LD. The in vitro release mechanism of the peptide was shown to be controlled either by kinetics of polymer mass loss or by a second process, hypothesized to involve peptide desorption from the polymer. These data indicate spray drying can be optimized to prepare commercially relevant PLGA microsphere formulations for delivery of peptides, including the LHRHa, leuprolide.

Hot melt extrusion technology for improved dissolution, solubility and "spring-parachute" processes of amorphous self-micellizing solid dispersions containing BCS II drugs indomethacin and fenofibrate: Profiles and mechanisms.

Many strategies have been employed to improve oral drug delivery. One such approach involves the use of supersaturable delivery systems such as amorphous self-micellizing solid dispersions (SmSDs). SmSDs have attracted more attention recently, but little is known regarding the impact of production methods on profiles and internal mechanisms of final SmSDs in spite of its importance. In this study, amorphous SmSDs containing self-micellizing Soluplus® and BCS II drug (either indomethacin (IND) or fenofibrate (FEN)) were generated using various methods: solvent evaporation (SOL), freeze-drying (FD), microwave radiation-quench cooling (MQC), and hot melt extrusion (HME). Microscopic morphology, amorphous state, thermal behavior, dissolution/solubility, and "spring-parachute" data were used to assemble physicochemical profiles for SmSD systems prepared using each method. Analysis of intermolecular interactions, solubilization, and crystallization inhibition further uncovered internal mechanisms explaining observed physicochemical properties. Generally, SmSD/IND and SmSD/FEN systems generated using HME exhibited superior dissolution, solubility, and spring-parachute profiles. The superior advantages of HME-generated SmSD/IND systems were attributed to relatively stronger intermolecular interactions than observed in SmSD/IND systems fabricated using other methods. Moreover, self-micellizing Soluplus® carrier was able to solubilize IND or FEN and suppress drug crystallization from a supersaturated state, which seemed to be an important mechanism for the properties enhancement caused by SmSD/FENHME. This knowledge should be useful for guiding further development of self-micellizing solid dispersions and for gaining deeper understanding of how HME technology can improve supersaturable drug delivery based on SmSDs strategy.

Deepened cellular/subcellular interface penetration and enhanced antitumor efficacy of cyclic peptidic ligand-decorated accelerating active targeted nanomedicines.

INTRODUCTION: Acceleration and improvement of penetration across cell-membrane interfaces of active targeted nanotherapeutics into tumor cells would improve tumor-therapy efficacy by overcoming the issue of poor drug penetration. Cell-penetrating peptides, especially synthetic polyarginine, have shown promise in facilitating cargo delivery. However, it is unknown whether polyarginine can work to overcome the membrane interface in an inserted pattern for cyclic peptide ligand-mediated active targeting drug delivery. Here, we conducted a study to test the hypothesis that tandem-insert nona-arginine (tiR9) can act as an accelerating component for intracellular internalization, enhance cellular penetration, and promote antitumor efficacy of active targeted cyclic asparagine-glycine-arginine (cNGR)-decorated nanoliposomes. METHODS: Polyarginine was coupled with the polyethylene glycol (PEG) chain and the cNGR moiety, yielding a cNGR-tiR9-PEG2,000-distearoylphosphatidylethanolamine conjugate. RESULTS: The accelerating active targeted liposome (Lip) nanocarrier (cNGR-tiR9-Lip-doxorubicin [Dox]) constructed in this study held suitable physiochemical features, such as appropriate particle size of ~150 nm and sustained-release profiles. Subsequently, tiR9 was shown to enhance cellular drug delivery of Dox-loaded active targeted systems (cNGR-Lip-Dox) significantly. Layer-by-layer confocal microscopy indicated that the tandem-insert polyarginine accelerated active targeted system entry into deeper intracellular regions based on observations at marginal and center locations. tiR9 enhanced the penetration depth of cNGR-Lip-coumarin 6 through subcellular membrane barriers and caused its specific accumulation in mitochondria, endoplasmic reticulum, and Golgi apparatus. It was also obvious that cNGR-tiR9-Lip-Dox induced enhanced apoptosis and activated caspase 3/7. Moreover, compared with cNGR-Lip-Dox, cNGR-tiR9-Lip-Dox induced a significantly higher antiproliferative effect and markedly suppressed tumor growth in HT1080-bearing nude mice. CONCLUSION: This active tumor-targeting nanocarrier incorporating a tandem-insert polyarginine (tiR9) as an accelerating motif shows promise as an effective drug-delivery system to accelerate translocation of drugs across tumor-cell/subcellular membrane barriers to achieve improved specific tumor therapy.

Taming the Wildness of "Trojan-Horse" Peptides by Charge-Guided Masking and Protease-Triggered Demasking for the Controlled Delivery of Antitumor Agents.

Cell-penetrating peptide (CPP), also called "Trojan Horse" peptide, has become a successful approach to deliver various payloads into cells for achieving the intracellular access. However, the "Trojan Horse" peptide is too wild, not just to "Troy", but rather widely distributed in the body. Thus, there is an urgent need to tame the wildness of "Trojan Horse" peptide for targeted delivery of antineoplastic agents to the tumor site. To achieve this goal, we exploit a masked CPP-doxorubicin conjugate platform for targeted delivery of chemotherapeutic drugs using charge-guided masking and protease-triggered demasking strategies. In this platform, the cell-penetrating function of the positively CPP (d-form nonaarginine) is abrogated by a negatively shielding peptide (masked CPP), and between them is a cleavable substrate peptide by the protease (MMP-2/9). Protease-triggered demasking would occur when the masked CPP reached the MMP-2/9-riched tumor. The CPP-doxorubicin conjugate (CPP-Dox) and the masked CPP-Dox conjugate (mCPP-Dox) were used as models for the evaluation of masking and demasking processes. It was found that exogenous MMP-2/9 could effectively trigger the reversion of CPP-cargo in this conjugate, and this trigger adhered to the Michaelis-Menten kinetics profile. This conjugate was sensitive to the trigger of endogenous MMP-2/9 and could induce enhanced cytotoxicity toward MMP-2/9-rich tumor cells. In vivo antitumor efficacy revealed that this masked conjugate had considerable antitumor activity and could inhibit the tumor growth at a higher level relative to CPP-cargo. Low toxicity in vivo showed the noticeably decreased wildness of this conjugate toward normal tissues and more controllable entry of antitumor agents into "Troy". On the basis of analyses in vitro and in vivo, this mCPP-cargo conjugate delivery system held an improved selectivity toward MMP-2/9-rich tumors and would be a promising strategy for tumor-targeted treatment.