Novel composite fatty acid vesicles-in-Pluronic lecithin organogels for enhanced magnolol delivery in skin cancer treatment.

A novel composite carrier composed of Pluronic lecithin organogels and fatty acid vesicles was used to enhance the stability and facilitate the topical delivery of a natural bioactive drug, magnolol (Mag), for treatment of skin cancer. Jojoba oil was incorporated in the organogel (OG) base to provide a synergistic effect in treatment of skin cancer. The organoleptic properties, rheological behavior, morphology, and drug content of the OG formulations were investigated with emphasis on the impact of vesicle loading on the OG characteristics. The effect of OG on Mag release and ex-vivo permeation studies were evaluated and compared to free Mag in OG. The biological anti-tumor activity of the OG formulae was assessed using a skin cancer model in mice. All OG formulations exhibited uniform drug distribution with drug content ranging from 92.22 ± 0.91 to 100.45 ± 0.77 %. Rheological studies confirmed the OG shear-thinning flow behavior. Ex-vivo permeation studies demonstrated that the permeation of Mag from all OG formulations surpassed that obtained with free Mag in the OG. The anti-tumor activity studies revealed the superior efficacy of 10-hydroxy-decanoic acid (HDA)-based vesicles incorporated in OG formulations in mitigating 7,12- dimethylbenz(a)anthracene (DMBA)-induced skin cancer, thereby offering a promising platform for the local delivery of Mag.

Inhalable DNase I microparticles engineered with biologically active excipients.

Highly viscous mucus poses a big challenge for the delivery of particulates carrying therapeutics to patients with cystic fibrosis. In this study, surface modifying DNase I loaded particles using different excipients to achieve better lung deposition, higher enzyme stability or better biological activity had been exploited. For the purpose, controlled release microparticles (MP) were prepared by co-spray drying DNase I with the polymer poly-lactic-co-glycolic acid (PLGA) and the biocompatible lipid surfactant 1,2-dipalmitoyl-Sn-phosphatidyl choline (DPPC) using various hydrophilic excipients. The effect of the included modifiers on the particle morphology, size, zeta potential as well as enzyme encapsulation efficiency, biological activity and release had been evaluated. Powder aerosolisation performance and particle phagocytosis by murine macrophages were also investigated. The results showed that more than 80% of enzyme activity was recovered after MP preparation and that selected surface modifiers greatly increased the enzyme encapsulation efficiency. The particle morphology was greatly modified altering in turn the powders inhalation indices where dextran, ovalbumin and chitosan hydrochloride increased considerably the respirable fraction compared to the normal hydrophilic carriers lactose and PVP. Despite of the improved aerosolisation caused by chitosan hydrochloride, yet retardation of chitosan coated particles in artificial mucus samples discouraged its application. On the other hand, dextran and polyanions enhanced DNase I effect in reducing cystic fibrosis mucus viscosity. DPPC proved good ability to reduce particles phagocytic uptake even in the presence of the selected adjuvants. The prepared MP systems were biocompatible with lung epithelial cells. To conclude, controlled release DNase I loaded PLGA-MP with high inhalation indices and enhanced mucolytic activity on CF sputum could be obtained by surface modifying the particles with PGA or dextran.

Polypeptide and glycosaminoglycan polysaccharide as stabilizing polymers in nanocrystals for a safe ocular hypotensive effect.

Improved ocular delivery of a poorly soluble anti-glaucoma drug, acetazolamide (ACZ), in a stable nanosuspension (NS) was the main target of the study. The anionic polypeptide, poly-γ-glutamic acid (PG) and the glycosaminoglycan, hyaluronic acid, were used to stabilize ACZ-NS prepared using the antisolvent precipitation (AS-PT) coupled with sonication technique. To endue in site biocompatibility with high tolerability, soya lecithin (SL) phospholipid has been also combined with polyvinyl alcohol (PVA). NS with uniform PS in the range 100-300 nm, high ζ > ±20 mV, and enhanced saturation solubility were produced. Targeting solvent removal with control on future particle growth, post-production processing of NS was done using spray drying. The carriers' composition and amount relative to ACZ-NS were optimized to allow for the production of a redispersible dry crystalline powder. Particles crystallinity was confirmed using X-ray powder diffraction (XRPD) and differential scanning calorimetry (DSC) in liquid and spray dried NS. The modified Draize test proved the safety and tolerability following application to rabbit eyes accompanying an efficient ocular hypotensive activity using a steroid glaucoma model.

Near IR responsive targeted integrated lipid polymer nanoconstruct for enhanced magnolol cytotoxicity in breast cancer.

Advances in cancer nanotechnology aim at improving specificity and effectiveness for tumor treatment. Amalgamation of different treatment modalities is expected to provide better cancer combating. Herein, We developed a long circulating nanocarrier comprising trastuzumab (TZB) surface modified polylactic-co-glycolic acid (PLGA) nanoparticles (NPs) co-encapsulating magnolol (Mag) and gold nanoparticles (GNPs). A modified single step nanoprecipitation method was adopted ensuring particle coating with D-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) while co-encapsulating GNPs. TZB was then anchored on NPs surface using a carbodiimide chemistry. The cytotoxicity of the developed system was evaluated with and without photothermal irradiation. NPs cellular uptake was then followed using confocal microscopical imaging. A hybrid matrix composed of PLGA/TPGS and surface decorated with TZB with a conjugation efficiency of ˃65%, was confirmed via FTIR, 1HNMR. GNPs could only be included in the NPs, when placed in the organic phase as evidenced by the shifted GNPs surface plasmonic resonance and confirmed via imaging coupled with energy dispersive X-ray analysis. Optimized NPs (136.1 ± 1.3 nm, -8.2 ± 1 mV and Mag encapsulation efficiency of 81.4 ± 1.8%) were able to boost Mag cytotoxicity on breast cancer cells while providing a selective multifunctional therapy with an added photothermal effect.

Pharmacokinetic/pulmokinetic analysis of optimized lung targeted spray dried ketotifen-dextran core shell nanocomplexes-in-microparticles.

A passive lung targeted system for controlled lung delivery of ketotifen (KT) was developed based on the green complexation of dextran sulphate (DS) and KT. Achieving deep lung deposition of high drug fraction, while evading lung defense mechanisms were set as goals. Optimized uniform negatively charged nanocomplexes (NC), <80 nm, were obtained at KT/DS weight ratio of 1:0.66 to 1:0.5 and 1% surfactant concentration with 90% drug complexation efficiency. The interaction between KT and DS and matrix formation were evidenced by Fourier-transform infrared (FT-IR) spectra and differential scanning calorimetry (DSC) studies. A respirable particle percent reaching 67.41 ±â€¯2.6% was obtained following co-spray drying NC containing poloxamer with leucine. A higher lung/plasma partitioning was obtained following pulmonary administration of selected nanocomplexes in microparticles (NCEMP) to rats compared to oral and intravenous (iv) routes. A new core shell nanocomplex formed of DS and KT as main substrates exhibited a potential for lung targeting of the anti-asthmatic drug.

Construction and immunogenicity analysis of nanoparticulated conjugate of heat-stable enterotoxin (STa) of enterotoxigenic Escherichia coli.

The ultimate goal of this research was to overcome the low immunogenicity of the biological macromolecule (heat stable enterotoxin STa) via its conjugation to biodegradable PLGA nanoparticles (NP). STa was first isolated from Enterotoxigenic Escherichia coli (ETEC), purified and identified using reported HPLC procedures. Optimized homogenous PLGA NP, prepared using the nanoprecipitation technique were used for conjugating STa using the carbodiimide synthesis. Covalent binding of STa to PLGA NP was confirmed via FTIR and 1HNMR analysis. Safety and tolerability of the developed nanoparticulated STa-PLGA conjugate were confirmed by MTT assay on A549 lung cancer cells. After subcutaneous immunization, STA-PLGA NP conjugate induced a significant immune response in mice showing a strong binding and neutralizing antibody titer. The developed novel STa-PLGA NP conjugate is expected to provide promising protection against enterotoxigenic Escherichia coli (ETEC).

Polymer-Based Novel Lung Targeted Delivery Systems.

BACKGROUND: Due to its unique features, the respiratory tract had received great attention as a promising non-invasive route for drug administration to achieve both local and systemic effects. Efforts spent to tailor systems able to overcome the lung defence mechanisms and biological barriers are followed in this review. Aerodynamic diameter, morphology, lung deposition and drug release profiles are the main criteria describing the selected new smart lung targeted delivery systems. METHODS: Novel systems such as nanoparticles, nano-embedded-in microparticles (NEM), small microparticles (MP), large porous particles (LPP), PulmospheresTM and polymeric micelles are used to passively target different areas in the respiratory tract. The most common preparation methods are outlined in the article. Special emphasis was given to the characteristics of the polymers used to fabricate the developed systems. Efforts made to prepare systems using chitosan (CS), alginate (alg), hyaluronic acid (HA), gelatin and albumin as examples of natural polymers and poly lactic-co-glycolic acid (PLGA) and poly(Ɛ-caprolactone) (PCL) as synthetic polymers were compiled. CONCLUSION: The continuous development and work in the area of lung targeting resulted in the development of engineered smart platforms with the capability to carry small drug molecules, proteins and genes to treat a variety of local and systemic diseases.

Why human prepuce is a valuable resource in science? Histological, ultrastructural, immunohistochemical and statistical analysis / ¿Por qué el prepucio humano es un recurso valioso en la ciencia? Análisis histológicos, ultraestructurales, inmunohistoquímicos y estadísticos

SUMMARY: This research was to examine the histological and ultrastructural characteristics of prepuce samples, as well as vimentin and S100 protein localization and statistical analysis. Urologists have long struggled with the prepuce, which is used to treat a variety of urethral problems. Skin biopsies were collected from the prepuce at the moment of circumcision and processed for light microscopy, electron microscope examination, immunohistochemical techniques, and statistical analysis in a total of six boys. Histologically, the prepuce epidermis displayed focal spiky ridges, which are saw-toothed interspersed with sulci, slight hyperpigmentation, looser connective tissue and plentiful vascular components. Immunohistochemically, the existence of melanocytes and Langerhans cells in the epidermis, as well as smooth muscles in the dermis, was stained positively for vimentin. Also, there was a positive reactivity of the Langerhans cells in the epidermis and around Meissner's corpuscles in the dermis for S100 protein staining. Ultrastructurally, the prepuce's intercellular gaps were widened, melanocytes rested on a folded basement membrane, and desmosomal content was reduced, with a prominent active euchromatic nucleus. Cytoplasmic projections were distended and elongated, and the interstitial blood vessels were surrounded by endothelial cells and rested on a basement membrane. There were also minimal collagen fibers in the interstitium. The prepuce's histological and ultrastructural features, as well as immunohistological studies using vimentin and S100 protein as intermediate filaments and statistical analysis, all demonstrated that it is a useful scientific resource.

RESUMEN: El presente trabajo de investigación se realizó para examinar las características histológicas y ultraestructurales de las muestras de prepucio, así como la localización y el análisis estadístico de la vimentina y la proteína S100. Los urólogos han intentado trabajar durante mucho tiempo con el prepucio, que se usa para tratar una variedad de problemas uretrales. Se recolectaron biopsias de piel del prepucio de seis niños en el momento de la circuncisión y se procesaron para microscopía óptica, examen con microscopio electrónico, técnicas inmunohistoquímicas y análisis estadístico. Histológicamente, la epidermis del prepucio mostraba crestas puntiagudas focales, intercaladas con surcos, hiperpigmentación leve, tejido conectivo más laxo y abundantes componentes vasculares. Inmunohistoquímicamente, la existencia de melanocitos y células dendríticas epidérmicas (células de Langerhans), así como músculo liso en la dermis, se tiñeron positivamente para vimentina. Además, hubo una reactividad positiva de las células dendríticas epidérmicas en la epidermis y alrededor de los corpúsculos del tacto (de Meissner) en la dermis para la tinción de la proteína S100. Ultraestructuralmente, los espacios intercelulares del prepucio se ensancharon, los melanocitos descansaban sobre una membrana basal plegada y el contenido desmosómico se redujo, con un núcleo eucromático activo prominente. Las proyecciones citoplasmáticas estaban distendidas y alargadas, y los vasos sanguíneos intersticiales estaban rodeados por células endoteliales y descansaban sobre una membrana basal. También había fibras de colágeno mínimas en el intersticio. Las características histológicas y ultraestructurales del prepucio, así como los estudios inmunohistológicos utilizando vimentina y proteína S100 como filamentos intermedios y el análisis estadístico, demostraron que es un recurso científico útil.

Dextran-based Nanocarriers for Delivery of Bioactives.

BACKGROUND: Dextran (DX) is a natural polysaccharide produced in the laboratory by fermentation of sucrose under the effect of the enzyme DX sucrase (1,6-α-D-glucan-α- glucosyltransferase). After harvesting and purification DX is subjected to cracking and separation to obtain the desired molecular weight. METHODS: The hydroxyl groups present in DX offer many sites for derivatization allowing the production of functionalized glycoconjugates biocompatible compound. DX and its derivatives are getting increased attention for use in core decoration or as carriers in novel drug delivery systems. This includes, among others, ion-pairing, self-aggregate, protein and drug conjugates. DX carriers and camouflaged particles will be dealt with in this review to give emphasis on the great versatility of this natural biocompatible polysaccharide. CONCLUSION: With the continuous development in the area of drug delivery, we believe that the unique properties of this versatile nanocarrier platform will elect it as one of the cornerstones of safe nanodelivery systems.

Lecithin/TPGS-based spray-dried self-microemulsifying drug delivery systems: In vitro pulmonary deposition and cytotoxicity.

The aim of the present work was to develop a new solid self-microemulsifying drug delivery system (SMEDDS) for the pulmonary delivery of the poorly water-soluble anti-cancer drug atorvastatin (AVT). Microemulsion (ME) was first developed using isopropyl myristate (IPM), a combination of 2 biocompatible surfactants: lecithin/d-α-tocopheryl polyethylene glycol succinate (TPGS) and ethanol as co-surfactant. Two types of lecithin with different phosphatidylcholine (PC) contents were compared. Phase diagram, physico-chemical characterization and stability studies were used to investigate ME region. Solid SMEDDS were then prepared by spray-drying the selected ME using a combination of carriers composed of sugars, leucine as dispersibility enhancer with or without polyethylene glycol (PEG) 6000. Yield, flow properties, particle size and in vitro pulmonary deposition were used to characterize the spray-dried powders. Reconstituted MEs were characterized in terms of morphology, particle size and size distribution. In vitro cytotoxicity study was undertaken on lung cancer cell line for the selected MEs and SD-SMEDDS formulae. Results showed that the most satisfactory MEs properties were obtained with 1:3 lecithin/TPGS, 1:1 lecithin/oil and 1:1 surfactant/co-surfactant ratios. A larger ME area was obtained with lecithin containing 100% PC compared to the less expensive lecithin containing 20% PC. By manipulating spray drying parameters, carrier composition and ratio of ME lipids to carrier, microparticles with more than 70% of respirable fraction could be prepared. The ME was efficiently recovered in simulated lung fluid even after removal of alcohol. The concurrent delivery of AVT with TPGS in solid SMEDDS greatly enhanced the cytotoxic activity on lung cancer cells.

Defining cisplatin incorporation properties in thermosensitive injectable biodegradable hydrogel for sustained delivery and enhanced cytotoxicity.

Injectable thermoreversible chitosan (CS)/ß-glycerophosphate (ß-GP) hydrogels were developed for prolonged localized delivery of cisplatin (Cis). The effects of formulation variables on the thermoreversible hydrogels preparation as well as the impact of drug incorporation method on Cis release were studied. Antitumor activity of Cis CS/ß-GP thermoreversible hydrogels were evaluated against HCT-116 human colorectal cancer cells and MCF-7 human breast cancer cells. Incorporation of Cis to CS solution adjusted at pH 6.2 prior to hydrogel preparation deemed necessary to achieve a sustained release up to 4 days. Cis loaded CS/ß-GP thermoreversible hydrogels showed enhanced antitumor activity with about 1.2 fold and 2.05 fold that of Cis solution against HCT-116 cancer cells and MCF-7 cancer cells respectively. The obtained enhanced antitumor activity elected this delivery system for further in vivo and toxicological investigations.

Spray dried inhalable ciprofloxacin powder with improved aerosolisation and antimicrobial activity.

In this study, the spray drying technique was used to prepare ciprofloxacin microparticles (CFX-MPs) for pulmonary administration. By virtue of its amphoteric properties, CFX was dissolved in either a slightly alkaline or acidic solution depending on the used polymer. Dextran and chitosan were used to prepare the MPs and modify the release characteristics of the drug. Particle surface modification was done with either DPPC or PEG. The effects of the manufacturing and formulation parameters on the drug-polymer interactions were investigated by thermal analysis and infrared spectroscopy. CFX-MPs showed improved aerosolisation properties and the encapsulated drug possessed high antimicrobial activity against two of the common and resistant respiratory pathogens: Pseudomonas aeruginosa and Staphylococus aureus. MPs were safe on the lung epithelial cells. Modulation of particle characteristics and drug release was possible by altering not only the polymer but also the type of the acid from which the powders were spray dried. MPs prepared with glutamic and aspartic acids showed better characteristics than those prepared with acetic and hydrochloric acids. Dextran modified particles showed improved aerosolisation properties and safety on lung epithelial cells.

Enhanced properties of discrete pulmonary deoxyribonuclease I (DNaseI) loaded PLGA nanoparticles during encapsulation and activity determination.

In the present work, DNaseI loaded poly(lactic-co-glycolic acid) (PLGA) nanoparticles (NPs) for pulmonary delivery were prepared using emulsion solvent evaporation. The effects of the various formulation and experimental variables on the size and morphological characteristics of the particles as well as on the encapsulation efficiency were investigated. The stability of the encapsulated DNaseI was evaluated and the respirable fraction was determined. Cytotoxicity of the NPs was evaluated on lung epithelial cells. The results showed that by using leucine and dipalmito-phosphatidyl-choline (DPPC), discrete NPs with 76% retained biological activity were prepared. A high respirable fraction (particles below 6 µm) reaching 71.3% was achieved after nebulization of the NP suspension. The results revealed the suitability of the prepared particles for pulmonary delivery and highlighted the role of excipients in the stabilization of DNaseI against the stresses encountered during preparation.