(Molecular pharmaceutics[TA]) articles in PubMed
- Design and synthesis of new cell penetrating peptides: diffusion and distribution inside the cornea. [Journal Article]
- Mol Pharm 2016 Sep 27MP
- The role of cell penetrating peptides (CPPs) has been challenged in recent years for drug delivery to ocular tissues for the targeting of both anterior and posterior segments. The enhancement of tran...
The role of cell penetrating peptides (CPPs) has been challenged in recent years for drug delivery to ocular tissues for the targeting of both anterior and posterior segments. The enhancement of trans-corneal transport for anterior segment targeting is a very important issue possibly leading to important outcomes on efficacy and to the opportunity of topical administration of molecules with unfavourable penetration properties. The aim of the present work was the design and synthesis of new CPPs, deriving from the structure of PEP-1 peptide. Synthesized peptides were labelled with 5-carboxyfluorescein (5-FAM) and their diffusion behaviour and distribution inside the cornea were evaluated by a validated ex vivo model and a confocal microscopy approach. Newly synthesized peptides showed similar corneal permeation profiles than PEP-1 (Papp=0.75±0.56*10(-6) cm/s), about 2.6-fold higher than 5-FAM (Papp=0.29±0.08*10(-6) cm/s) despite the higher molecular weight. Confocal microscopy experiments highlighted the tendency of PEP-1 and its derived peptides to localise in the intercellular space and/or in the plasma membrane. Noteworthy, using penetratin as positive control, a higher trans-corneal permeation (Papp=6.18±1.46*10(-6) cm/s) was evidenced together with a diffusion by intracellular route and a different accumulation between wings and basal epithelial cells, probably depending on the stage of cell development. Finally, PEP-1 and pep-7 proved to be safe and well tolerated when tested on human conjuctival cell line.
- Targeting the neuropeptide Y1 receptor for cancer imaging by positron emission tomography using novel truncated peptides. [Journal Article]
- Mol Pharm 2016 Sep 26MP
- The neuropeptide Y1 receptor (Y1R) is overexpressed in many human cancers, particularly breast cancer. Due to stability issues, limited success has been achieved for Y1R imaging agents, including ful...
The neuropeptide Y1 receptor (Y1R) is overexpressed in many human cancers, particularly breast cancer. Due to stability issues, limited success has been achieved for Y1R imaging agents, including full length and truncated neuropeptide Y (NPY) analogues. The goal of this study was to evaluate the possibility of using radiolabeled truncated NPY analogues to visualize Y1R expression in a preclinical model of Y1R-positive tumor. Four truncated NPY analogues were synthesized based on the sequence of [Pro30, Tyr32, Leu34]NPY(28-36), also known as BVD15. We substituted Tyr5 and Arg6 with unnatural amino acids aiming to enhance plasma stability while maintain good receptor binding affinity to Y1R. In addition, we substituted Leu4 to Lys4 in order to conjugate via an optional linker the DOTA chelator for 68Ga labeling. Receptor binding affinity and plasma stability of these compounds were evaluated. Positron emission tomography/computed tomography (PET/CT) imaging and biodistribution studies were performed using immune-compromised mice bearing HEK293T::WT and HEK293T::hY1R tumors. [Lys(Ga-DOTA)4, Bip5]BVD15 (CCZ01035), [Lys(Ahx-Ga-DOTA)4, Bip5]BVD15 (CCZ01053), and [Lys(Pip-Ga-DOTA)4, Bip5]BVD15 (CCZ01055) demonstrated good binding affinity to Y1R (Ki = 23.4 - 32.3 nM), while [Lys(Ga-DOTA)4, Har6]BVD15 (P05067) showed poor binding affinity (Ki > 1,000 nM). In addition, CCZ01055 exhibited low binding affinity (Ki > 1,000 nM) to Y2R and Y4R, demonstrating its selectivity to Y1R. The former three peptides showed improved in vitro plasma stability of 7-16% remaining intact after 1 h incubation. PET/CT imaging and biodistribution studies for 68Ga-labeled CCZ01053, CCZ01035 and CCZ01055 showed that radioactivity was mainly cleared by the renal pathway, and HEK293T::hY1R tumors were clearly visualized with minimal background activity with the latter two. Of these two tracers, [68Ga]CCZ01055 provided lower kidney accumulation and higher contrast, i.e. average uptake ratios of Y1R tumor to wild type tumor, blood and muscle are 3.87 ± 0.83, 4.12 ± 1.14 and 17.6 ± 4.64, respectively. Furthermore, Y1R tumor uptake with [68Ga]CCZ01055 was significantly reduced with co-injection of 100 μg peptide YY, confirming the specificity of tumor accumulation was receptor mediated. We successfully developed the first Y1R-targeting truncated NPY analogues for PET imaging in a preclinical model, and [68Ga]CCZ01055 is a critical template for designing improved imaging agents to detect Y1R expressing cancers.
- Brain Targeting of Temozolomide via the Intranasal Route Using lipid based nanoparticle: Brain Pharmacokinetic and Scintigraphic Analysis. [Journal Article]
- Mol Pharm 2016 Sep 23MP
- The aim of the present work was to investigate the efficacy of temozolomide nanostructured lipid carriers (TMZ-NLCs) to enhance brain targeting via nasal route. The formulation was optimized by apply...
The aim of the present work was to investigate the efficacy of temozolomide nanostructured lipid carriers (TMZ-NLCs) to enhance brain targeting via nasal route. The formulation was optimized by applying four factor three levels Box Behnken design. The developed formulations and their functional relationships between independent variables on dependent variables were observed. The independent variables used in the formulation were gelucire (X1), liquid lipid:total lipid (X2) tween 80 (X3), sonication time (X4) and their effect were observed on size (Y1), % drug release (Y2) and drug loading (Y3). The optimized TMZ-NLC was further evaluated for surface morphology, ex-vivo permeation study and in vivo study. The all TMZ-NLC formulations showed size in nanometer range with high drug load and prolonged drug release. The optimized formulation (TMZ-NLCopt) showed entrapment efficiency (81.64 ± 3.71%), zeta potential (15.21± 3.11mV) and poly dispersity index (less than 0.2). The enhancement ratio was found to be 2.32 times in comparison to control formulation (TMZ-dis). The in-vivo study in mice showed brain/blood ratio of TMZ-NLCopt (i.n.) was found to be significantly higher as compared with TMZ disp (i.n, i.v.). The scintigraphy image of mice brain showed presence of high concentration of TMZ. The AUC ratio of TMZ-NLCopt to TMZ-dis in the brain was the highest among the organs. The finding of this study substantiates the existence of direct nose-to-brain delivery route for NLCs.
- Synthesis and Biological Activity of Highly Cationic Dendrimer Antibiotics. [Journal Article]
- Mol Pharm 2016 Sep 23MP
- The development of pathogenic bacteria resistant to current treatments is a major issue facing the world today. Here, the synthesis and biological activity of fourth generation poly(amidoamine) dendr...
The development of pathogenic bacteria resistant to current treatments is a major issue facing the world today. Here, the synthesis and biological activity of fourth generation poly(amidoamine) dendrimers decorated with 1-hexadecyl-azoniabicylo[2.2.2]octane (C16-DABCO), a quaternary ammonium compound known to have antibacterial activity, are described. This highly cationic dendrimer antibiotic was tested against several Gram positive and Gram negative strains of pathogenic bacteria and exhibited activity against both. Higher activity toward the Gram positive strains that were tested was observed. After the antimicrobial activity was assessed, E. coli and B. cereus were subjected to a resistance selection study. This study demonstrated that a multivalent approach to antimicrobial design significantly reduces the likelihood of developing bacterial resistance. Highly cationic dendrimers were also used as pretreatment of a membrane in order to prevent biofilm formation.
- Optimization and <i>in vivo</i> validation of peptide-vectors targeting the LDL-receptor. [Journal Article]
- Mol Pharm 2016 Sep 22MP
- Active targeting and delivery to pathophysiological organs of interest is of paramount importance to increase specific accumulation of therapeutic drugs or imaging agents while avoiding systemic side...
Active targeting and delivery to pathophysiological organs of interest is of paramount importance to increase specific accumulation of therapeutic drugs or imaging agents while avoiding systemic side-effects. We recently developed a family of new peptide ligands of the human and rodent LDL-receptor (LDLR), an attractive cell-surface receptor with high uptake activity and local enrichment in several normal or pathological tissues (Malcor et al., </i>J Med Chem<i> 2010). Initial chemical optimization of the 15-mer, all natural amino acids compound 1/VH411 (DSGL-[CMPRLRGC]<sub>c</sub>DPR) and structure-activity relationship (SAR) investigation led to the cyclic 8-amino acid analogue compound 22/VH445 ([cMPRLRGC]<sub>c</sub>) which specifically binds hLDLR with a </i>K<i><sub>D</sub> of 76 nM and has an </i>in vitro<i> blood half-life of ~3 hrs. Further introduction of non-natural amino acids led to the identification of compound 60/VH4106 ([(D)-"Pen"M"Thz"RLRGC]c) that showed the highest </i>K<i><sub>D</sub> value of 9 nM. However, this latter analogue displayed the lowest </i>in vitro<i> blood half-life (~1.9 hrs). In the present study, we designed a new set of peptide analogues, namely VH4127 to VH4131, with further improved biological properties. Detailed analysis of the hLDLR-binding kinetics of previous and new analogues showed that the latter all displayed very high on-rates, in the 10<sup>6</sup> s<sup>-1</sup>.M<sup>-1</sup>, and off-rates varying from the low 10<sup>-2</sup> s<sup>-1</sup> to the 10<sup>-1</sup> s<sup>-1</sup> range. Furthermore, all these new analogues showed increased blood half-lives </i>in vitro<i>, reaching ~7 and 10 hrs for VH4129 and VH4131, respectively. Interestingly, we demonstrate in cell-based assays using both VH445 and the most balanced optimized analogue VH4127 ([cM"Thz"RLRG"Pen"]<sub>c</sub>), showing a </i>K<i><sub>D</sub> of 18 nM and a blood half-life of ~4.3 hrs, that its higher on-rate correlated with a significant increase in both the extent of cell-surface binding to hLDLR and the endocytosis potential. Finally, intravenous injection of tritium-radiolabelled 3H-VH4127 in wild-type or ldlr -/- mice confirmed their active LDLR-targeting </i>in vivo<i>. Overall, this study extends our previous work towards a diversified portfolio of LDLR-targeted peptide-vectors with validated LDLR-targeting potential </i>in vivo<i>.
- Increasing crosslinking density of core-crosslinked paclitaxel conjugated micelles compromises the anti-tumor effects against 2D and 3D tumor cellular models. [Journal Article]
- Mol Pharm 2016 Sep 21MP
- Paclitaxel (PTX) conjugated micelles provide a promising tool for the treatment of prostate cancer. Core-crosslinking by incorporating a disulfide bridge is a useful approach to improve the in vivo s...
Paclitaxel (PTX) conjugated micelles provide a promising tool for the treatment of prostate cancer. Core-crosslinking by incorporating a disulfide bridge is a useful approach to improve the in vivo stability of polymeric micelles. This paper aims to investigate the effects of different crosslinking degrees on the anti tumor efficacy of micelles formed by poly(ethylene glycol methyl ether acrylate)-b-poly(carboxyethyl acrylate) (POEGMEA-b-PCEA-PTX) block copolymer. Both 2D and 3D in vitro prostate tumor cell models were used to evaluate the uncrosslinked and crosslinked micelles. The cytotoxicity decreased with an increase in crosslinking degrees when tested with 2D cultured cells and all micelles remained less cytotoxic than free PTX. In the 3D prostate MCTS model, however, uncrosslinked micelles showed higher cytotoxicity than free PTX, but an increase in crosslinking density again decreased the antitumor efficacy of micelles. These results are contradictory to our previous research using an irreversible cross-linker (1,8-diaminooctane) to stabilize POEGMEA-b-PCEA-PTX conjugate micelles where it was shown that crosslinking accelerates and improves the effects of the micelles when compared to uncrosslinked micelles. Further studies are desired to investigate the underlying mechanisms of disulfide bonds when micelles are internalized into cells.
- VEGF and VEGFR2-targeted Liposomes for Cisplatin Delivery to Glioma Cells. [Journal Article]
- Mol Pharm 2016 Sep 21MP
- Targeted delivery of anticancer drugs to brain tumors, especially glioblastoma multiform, which is the most frequent and aggressive types, is one of the important objectives in nanomedicine. Vascular...
Targeted delivery of anticancer drugs to brain tumors, especially glioblastoma multiform, which is the most frequent and aggressive types, is one of the important objectives in nanomedicine. Vascular endothelial growth factor (VEGF) and its receptor type II (VEGFR2) are promising targets, because they are overexpressed by not only core cells but also by migrated glioma cells, which are responsible for resistance and rapid progression of brain tumors. The purpose of the present study was to develop the liposomal drug delivery system combining enhanced loading capacity of cisplatin and high binding affinity to glioma cells. This was achieved by using of highly soluble cisplatin analog, cis-diamminedinitratoplatinum(II), and antibodies against the native form of VEGF or VEGFR2 conjugated to surface of liposomes. The developed drug delivery system revealed sustained drug release profile, high affinity to antigens as well as increased uptake by glioma C6 and U-87 MG cells. Pharmacokinetic study on glioma C6-bearing rats revealed prolonged blood circulation time of the liposomal formulation. The above features enabled the present drug delivery system to overcome both poor pharmacokinetics typical for platinum formulations and low loading capacity typical for conventional liposomal cisplatin formulations.
- Precise Targeting of Liver Tumor Using Glycol Chitosan Nanoparticles: Mechanisms, Key Factors, and Their Implications. [Journal Article]
- Mol Pharm 2016 Sep 21MP
- Herein, we elucidated the mechanisms and key factors for the tumor-targeting ability of nanoparticles that presented high targeting efficiency for liver tumor. We used several different nanoparticles...
Herein, we elucidated the mechanisms and key factors for the tumor-targeting ability of nanoparticles that presented high targeting efficiency for liver tumor. We used several different nanoparticles with sizes of 200 - 300 nm, including liposome nanoparticles (LNPs), polystyrene nanoparticles (PNPs) and glycol chitosan-5β-cholanic acid nanoparticles (CNPs). Their sizes are suitable for the enhanced permeation and retention (EPR) effect in literature. Different in vitro characteristics, such as the particle structure, stability and bio-inertness were carefully analyzed with and without serum proteins. Also, pH-dependent tumor cell uptakes of nanoparticles were studied using fluorescence microscopy. Importantly, CNPs had sufficient stability and bio-inertness to maintain their nanoparticle structure in the blood stream and they also presented prolonged circulation time in the body (blood circulation half-life T1/2 = about 12.2 h), compared to the control nanoparticles. Finally, employing liver tumor-bearing mice, we also observed that CNPs had the excellent liver tumor-targeting ability in vivo, while LNPs and PNPs demonstrated lower tumor-targeting efficiency due to the non-specific accumulation in normal liver tissue. Liver tumor models were produced by laparotomy and direct injection of HT29 tumor cells into the left lobe of liver of athymic nude mice. This study provides valuable information concerning the key factors for the tumor-targeting ability of nanoparticles such as stability, bio-inertness, and rapid cellular uptake at targeted tumor tissues.
- Multi-Parametric Analysis of Oncology Drug Screening with Aqueous Two-Phase Tumor Spheroids. [Journal Article]
- Mol Pharm 2016 Sep 21MP
- Spheroids present a biologically relevant 3D model of avascular tumors and a unique tool for discovery of anti-cancer drugs. Despite being used in research laboratories for several decades, spheroids...
Spheroids present a biologically relevant 3D model of avascular tumors and a unique tool for discovery of anti-cancer drugs. Despite being used in research laboratories for several decades, spheroids are not routinely used in the mainstream drug discovery pipeline primarily due to the difficulty of mass-producing uniformly sized spheroids and intense labor involved in handling, drug treatment, and analyzing spheroids. We overcome this barrier using a polymeric aqueous two-phase microtechnology to robotically microprint spheroids of well-defined size in standard 384-microwell plates. We use different cancer cells and show that resulting spheroids grow over time and display characteristic features of solid tumors. We demonstrate the feasibility of robotic, high throughput screening of 25 standard chemotherapeutics and molecular inhibitors against tumor spheroids of three different cancer cell lines. This screening uses over 7,000 spheroids to elicit high quality dose-dependent drug responses from spheroids. To quantitatively compare performance of different drugs, we employ a multi-parametric scoring system using half-maximum inhibitory concentration (IC50), maximum inhibition (Emax), and area under the dose-response curve (AUC) to take into account both potency and efficacy parameters. This approach allows us to identify several compounds that effectively inhibit growth of spheroids and compromise cellular viability, and distinguish them from moderately effective and ineffective drugs. Using protein expression analysis, we demonstrate that spheroids generated with the aqueous two-phase microtechnology reliably resolve molecular targets of drug compounds. Incorporating this low-cost and convenient-to-use tumor spheroid technology in pre-clinical drug discovery will make compound screening with realistic tumor models a routine laboratory technique prior to expensive and tedious animal tests to dramatically improve testing throughput and efficiency, and reduce costs of drug discovery.
New Search Next
- Light Control of Insulin Release and Blood Glucose Using an Injectable Photoactivated Depot. [Journal Article]
- Mol Pharm 2016 Sep 21MP
- In this work we demonstrate that blood glucose can be controlled remotely through light stimulated release of insulin from an injected cutaneous depot. Human insulin was tethered to an insoluble but ...
In this work we demonstrate that blood glucose can be controlled remotely through light stimulated release of insulin from an injected cutaneous depot. Human insulin was tethered to an insoluble but injectable polymer via a linker which was based on the light cleavable DMNPE group. This material was injected into the skin of streptozotocin treated diabetic rats. We observed insulin being released into the bloodstream after a two minute trans-cutaneous irradiation of this site by a compact LED light source. Control animals treated with the same material, but in which light was blocked from the site showed no release of insulin into the bloodstream. We also demonstrate that additional pulses of light from the light source result in additional pulses of insulin being absorbed into circulation. A significant reduction in blood glucose was then observed. Together, these results demonstrate the feasibility of using light to allow for the continuously variable control of insulin release. This in turn has the potential to allow for the tight control of blood glucose without the invasiveness of insulin pumps and cannulas.