RESUMO
PURPOSE: Myricetin (MYR) flavonoid is well-recognized for its antioxidant, anti-inflammatory and anti-tumor potential. Introducing nanomedicine was the ultimate resort to solve the imperfections of this nutraceutical, namely solubility, stability and delivery issues. The study, thus, aims at developing inhalable microparticles comprising MYR solid lipid nanoparticles (SLNs) for lung cancer therapy. METHODS: A two-step preparation procedure starting with complexation of MYR with the phospholipid Lipoid-S100, followed by nanoencapsulation in Gelucire-based, surfactant-free SLNs was developed. SLNs were characterized in terms of physicochemical properties, MYR loading, release behavior as well as anti-tumor potential and cellular uptake. Respirable microparticles were then obtained by spray drying SLNs with carbohydrate carriers. Their size, flowability and pulmonary deposition pattern were assessed. RESULTS: Optimized SLNs were 75.98 nm in diameter with a zeta-potential of -22.5 mV, and an encapsulation efficiency of 84.5%. Attempts to ameliorate drug loading implicate MYR-phospholipid complexation (MYR-PH-CPX) prior to its entrapment in SLNs, which ensured 5-fold increase in drug loading. Viability assays were modified to guarantee MYR chemical stability. Superior antitumor activity of MYR-phospholipid-complex and 3-fold reduction in IC50 were accomplished with MYR-SLNs. This could be related to enhanced cellular uptake revealed by confocal imaging and doubled fluorescence intensity. SLNs entrapping MYR-PH-CPX were spray-dried with carbohydrate carriers to produce respirable microparticles. The latter ensured MMAD of 2.39 µm and span index of 1.84, in addition to good flowability and > 80% release over 8 h. Deposition experiments revealed MMAD of 2.77 µm, FPF of 81.23 and EF of 93% indicating particle deposition in the targeted bronchial region. CONCLUSIONS: The study highlights the ability of phospholipid-complex on the nanoencapsulation, cellular uptake and antitumor activity of MYR. Formulation of respirable microparticles gives promises of efficacious therapy of lung carcinoma.
Assuntos
Antineoplásicos/administração & dosagem , Portadores de Fármacos/química , Flavonoides/administração & dosagem , Neoplasias Pulmonares/tratamento farmacológico , Nanopartículas/química , Fosfolipídeos/química , Células A549 , Administração por Inalação , Antineoplásicos/metabolismo , Antineoplásicos/farmacologia , Sobrevivência Celular/efeitos dos fármacos , Composição de Medicamentos , Liberação Controlada de Fármacos , Flavonoides/metabolismo , Flavonoides/farmacologia , Humanos , Tamanho da Partícula , Solubilidade , Propriedades de Superfície , Distribuição TecidualRESUMO
Non-invasive brain therapy for chronic neurological disorders is in high demand. Vinpocetine (VIN) tablets for cerebrovascular degenerative disorders ensued < 7% oral bioavailability. The olfactory pathway (providing direct brain access) can improve VIN pharmacokinetic/pharmacodynamic profile. In this context, VIN hydrogels based on temperature-, pH-, and ion-triggered gelation in physiological milieu were formulated. Poloxamer-chitosan (PLX-CS) and carbopol-HPMC-alginate (CP-HPMC-SA) systems were optimized for appropriate gelation time, temperature, and pH. PLX-CS-hydrogels exhibited strong mucoadhesion for > 8 h, while CP-HPMC-SA hydrogels were mucoadhesive in simulated nasal fluid, owing to pH and ion-activated gelation. Along with prolonged mucosal residence, hydrogels confirmed sustained VIN release (> 24 h), especially from CP-HPMC-SA hydrogels. As proof of concept, brain exposure of intranasal VIN hydrogels was investigated in rats versus VIN-IV bolus. PLX-CS provided 146% increase in AUC0-30 and 3-fold maximum brain concentration (BCmax) relative to IV bolus. BCmax was reached after 4 h versus 1 h (IV bolus). CP-HPMC-SA hydrogel showed superior brain targeting efficiency (460%) and brain direct transport percentage (78.23%). VIN plasma pharmacokinetics confirmed 45-60% reduction in AUCplasma versus IV bolus, while PCmax of CP-HPMC-SA and PLX-CS represented 17 and 28% that of IV bolus, respectively. Olfactory-targeted hydrogels grant effective, sustainable VIN brain level with minimal systemic exposure, thus, assuring lower dose, dose frequency, side effects, and per se better patient compliance.
Assuntos
Encefalopatias/tratamento farmacológico , Encéfalo/metabolismo , Sistemas de Liberação de Medicamentos , Hidrogéis , Administração Intranasal , Alginatos/química , Animais , Encefalopatias/metabolismo , Quitosana/metabolismo , Derivados da Hipromelose/química , Masculino , Ratos , Temperatura , Alcaloides de Vinca/administração & dosagemRESUMO
The present study investigates the effect of the preparation method (four methods) and formulation additives (propylene glycol (PG) and cholesterol (CH)) on the entrapment efficiency (EE) of pyridoxine hydrochloride (vitamin B6 (VB6)), representing hydrophilic water-soluble low permeable vitamins, in unilamellar liposomes. The main aim is to compare determined EE with predicted values generated using a web-published, computational model. Results showed that among the different preparation methods, modified film hydration showed significantly higher EE (p < 0.05). With regard to formulation additives, PG (5% w/v) produced smaller vesicles size with narrow size distribution. Agreement between determined and model-generated EE values was more evident in formulae with narrow size distribution (polydispersity index (PdI) below 0.23). Formulae containing PG showed slightly higher determined than predicted EE values indicating vitamin-phospholipid bilayer interaction. Meanwhile, agreement between determined and predicted EE was limited to VB6-to-phospholipid ratio below (1.2:2). The comparison provided further insight into the usefulness of the prediction model factors affecting agreement between determined and predicted EE data.
Assuntos
Nanopartículas/química , Piridoxina/química , Lipossomas Unilamelares/química , Colesterol/química , Simulação por Computador , Composição de Medicamentos , Liberação Controlada de Fármacos , Interações Hidrofóbicas e Hidrofílicas , Tamanho da Partícula , Propilenoglicol/química , Propriedades de Superfície , ÁguaRESUMO
Biofilm formation transforms infections from acute to chronic, increasing patient mortality and significantly increasing healthcare costs. We are studying the prevalence of some virulence genes among methicillin resistant Staphylococcus aureus (MRSA) isolates relative to biofilm formation and the potential of photoactivated hypericin to treat these infections. Isolates were collected from three Egyptian governorates over seven months in 2011, 100 isolates were identified as MRSA. Biofilm formation was established using crystal violet staining and 2,3,5-triphenyl tetrazolium chloride reduction. Twenty two percent of the isolates formed biofilms, of which 68.2% were moderate to strong. The virulence genes were detected using polymerase chain reaction. spaX (x-region of protein A) was most prevalent. All biofilm-formers lacked cap5 (capsular polysaccharide 5), the other genes were: nuc (thermonuclease) > clfA (clumping factor) > spaIgG (IgG binding site of protein A), fnbA (fibronectin protein A), cap8 (capsular polysaccharide 8), agr (accessory-gene-regulator locus) > fnbB (fibronectin protein B). agr-locus was only found in 22.22% of moderate biofilm-formers, the remaining genes were almost equally prevalent among biofilm-formers and negative controls. Photoactivated hypericin efficiently inhibited 92.2-99.9% of biofilm viability, irrespective of the number of virulence genes. To conclude, biofilm formation, and treatment might be affected by a myriad of virulence factors rather than a single gene, however, photoactivated hypericin remains a potential antibiofilm approach.
Assuntos
Biofilmes/efeitos da radiação , Staphylococcus aureus Resistente à Meticilina/patogenicidade , Staphylococcus aureus Resistente à Meticilina/efeitos da radiação , Infecções Estafilocócicas/microbiologia , Proteínas de Bactérias/genética , Proteínas de Bactérias/metabolismo , Humanos , Staphylococcus aureus Resistente à Meticilina/fisiologia , Fotoquimioterapia , Infecções Estafilocócicas/terapia , Virulência , Fatores de Virulência/genética , Fatores de Virulência/metabolismoRESUMO
Introduction: Cystic fibrosis (CF) is associated with pulmonary Pseudomonas aeruginosa infections persistent to antibiotics. Methods: To eradicate pseudomonal biofilms, solid lipid nanoparticles (SLNs) loaded with quorum-sensing-inhibitor (QSI, disrupting bacterial crosstalk), coated with chitosan (CS, improving internalization) and immobilized with alginate lyase (AL, destroying alginate biofilms) were developed. Results: SLNs (140-205 nm) showed prolonged release of QSI with no sign of acute toxicity to A549 and Calu-3 cells. The CS coating improved uptake, whereas immobilized-AL ensured >1.5-fold higher uptake and doubled SLN diffusion across the artificial biofilm sputum model. Respirable microparticles comprising SLNs in carbohydrate matrix elicited aerodynamic diameters MMAD (3.54, 2.48 µm) and fine-particle-fraction FPF (65, 48%) for anionic and cationic SLNs, respectively. The antimicrobial and/or antibiofilm activity of SLNs was explored in Pseudomonas aeruginosa reference mucoid/nonmucoid strains as well as clinical isolates. The full growth inhibition of planktonic bacteria was dependent on SLN type, concentration, growth medium, and strain. OD measurements and live/dead staining proved that anionic SLNs efficiently ceased biofilm formation and eradicated established biofilms, whereas cationic SLNs unexpectedly promoted biofilm progression. AL immobilization increased biofilm vulnerability; instead, CS coating increased biofilm formation confirmed by 3D-time lapse confocal imaging. Incubation of SLNs with mature biofilms of P. aeruginosa isolates increased biofilm density by an average of 1.5-fold. CLSM further confirmed the binding and uptake of the labeled SLNs in P. aeruginosa biofilms. Considerable uptake of CS-coated SLNs in non-mucoid strains could be observed presumably due to interaction of chitosan with LPS glycolipids in the outer cell membrane of P. aeruginosa. Conclusion: The biofilm-destructive potential of QSI/SLNs/AL inhalation is promising for site-specific biofilm-targeted interventional CF therapy. Nevertheless, the intrinsic/extrinsic fundamentals of nanocarrier-biofilm interactions require further investigation.
Assuntos
Antibacterianos , Biofilmes , Quitosana , Lipossomos , Nanopartículas , Infecções por Pseudomonas , Pseudomonas aeruginosa , Biofilmes/efeitos dos fármacos , Pseudomonas aeruginosa/efeitos dos fármacos , Pseudomonas aeruginosa/fisiologia , Humanos , Infecções por Pseudomonas/tratamento farmacológico , Nanopartículas/química , Quitosana/química , Antibacterianos/farmacologia , Antibacterianos/química , Antibacterianos/farmacocinética , Portadores de Fármacos/química , Fibrose Cística/tratamento farmacológico , Fibrose Cística/microbiologia , Lipídeos/química , Lipídeos/farmacologia , Percepção de Quorum/efeitos dos fármacos , Células A549 , Alginatos/químicaRESUMO
OBJECTIVES: This study aimed to develop and implement a program wide active learning framework to guide active learning and assessment efforts in an entry-to-practice competency-based PharmD program. METHODS: The development of the framework involved three stages: i) creation of a framework aligned with the program's guiding principles; ii) provision of training and support to faculty and students, and iii) evaluation of students' and academic staff satisfaction using an online survey over two academic years (2022-2023). Data from this survey was analyzed descriptively. RESULTS: An active learning framework, that was aligned with the program's guiding principles while allowing for flexibility for individual teaching styles, was developed. It consisted of four stages: pre-class preparation, in-class work, pre-lab preparation and in-lab activities (emphasizing knowledge acquisition and competency development). Academic staff surveys reported higher satisfaction of staff in year 2 compared to year 3 of the program, with indications of further training on specific modalities. Students' satisfaction improved from year 2 to 3, particularly in areas related to class objectives, learning environment and feedback. CONCLUSION: The transformation of a curriculum that includes the evolution of the teaching and learning strategy is a complex long-term project that deserves continuing attention. Having frameworks in place helps the management, the instructors, and the students to understand the global direction, stay focused and support the implementation of competency-based education and student-centered learning.
RESUMO
Photodynamic therapy (PDT) to manage non-melanoma skin cancers has garnered great attention over the past few years. Hypericin (Hy) is a potent lipid-soluble photosensitiser with promising anticancer therapeutic activities. Nevertheless, its poor water-solubility, aggregation in biological systems and insufficient skin penetration restricted its effective exploitation. Herein, we report for the first-time encapsulation of Hy into lipid nanocapsules (Hy-LNCs), and then application of an AdminPen™ hollow microneedles (Ho-MNs) array and an in-house fabricated Ho-MN to enable efficient intradermal delivery. The physicochemical properties, photoactivity, ex vivo drug distribution and cellular uptake were evaluated. Results showed that Hy-LNCs were successfully formed with a particle size of 47.76 ± 0.49 nm, PDI of 0.12 ± 0.02, high encapsulation efficiency (99.67% ± 0.35), 396 fold higher photoactivity, 7 fold higher skin drug deposition, significantly greater cellular uptake and higher photocytotoxicity compared to free Hy. The therapeutic effect of Hy-LNCs was finally assessed in vivo using a nude mouse model with transplanted tumours. Interestingly, Hy-LNCs delivered by Ho-MN exhibited remarkable anti-tumour destruction (85.84%) after irradiation with 595 nm. This study showed that Ho-MNs-driven delivery of Hy-LNCs followed by irradiation could form a promising minimally invasive, effective and site-specific approach for managing non-melanoma skin cancers.
Assuntos
Nanocápsulas , Fotoquimioterapia , Neoplasias Cutâneas , Animais , Antracenos , Lipídeos/química , Camundongos , Nanocápsulas/química , Perileno/análogos & derivados , Fotoquimioterapia/métodos , Neoplasias Cutâneas/tratamento farmacológicoRESUMO
Systemic rheumatoid arthritis (RA) regimens fail to attain effective drug level at the affected joints and are associated with serious side effects. Herein, an attempt made to improve therapeutic outcomes of both leflunomide (LEF) which is a disease modifying antirheumatic and dexamethasone (Dex) through local delivery of combination therapy by intra-articular route. LEF and Dex were encapsulated in nanostructured lipid carriers (NLCs) and PLGA nanoparticles (NPs), respectively. Both nanocarriers were loaded into chitosan/ß glycerophosphate (CS/ßGP) thermo-sensitive hydrogels and injected intra-articularly in adjuvant induced RA rat model. Particle size of LEF NLCs and selected Dex NPs formulations were 200 and 119 nm, respectively. Dex NPs and LEF NLCs showed a sustained release profile for up to 58 and 17 days, respectively. After 14 days of treatment remarkable joint healing was observed for groups treated with Dex NPs in combination with either free LEF or LEF NLCs in CS/ßGP hydrogel. Joint diameter measurements, TNF α levels and histopathological examination of dissected joints showed comparable values to the negative control group. This might be attributed to the synergistic effect of drug combination besides the ability of nanocarriers loaded hydrogel to prolong joint residence time and enhance joint healing potential.
Assuntos
Antirreumáticos , Artrite Reumatoide , Quitosana , Preparações Farmacêuticas , Animais , Artrite Reumatoide/tratamento farmacológico , Sistemas de Liberação de Medicamentos , RatosRESUMO
Despite the potent clinical efficacy of linezolid (LNZ) against drug-resistant tuberculosis, its safety and tolerability remain of major concern. Our objective is to develop antitubercular inhalable LNZ nano-embedded microparticles. In this context, LNZ incorporated in non-structured lipid carriers (NLCs) was characterized in terms of colloidal, morphological, thermal, and release profiles. The potential of LNZ-NLCs to cross mucosal barriers and invade alveolar macrophages (AM, MH-S cells) was appraised. In vivo proof of concept was accomplished via orotracheal administration to mice. Respirable microparticles prepared by spray drying NLCs with diluents were assessed for their size, shape, flowability, aerosolization performance, and lung deposition pattern. NLCs (809-827 nm in size, zeta potential - 37.4 to - 58.9 mV) ensued 19% LNZ loading and pH-independent sustained release. Penetration studies revealed 73% LNZ crossing mucus within 1 h. Meanwhile, viability assay on A549 cells ensured an IC50 of 1.2 and 0.32 mg/mL for plain and LNZ-NLCs, respectively. CLSM confirmed phagocytosis of NLCs by MH-S macrophages, while H&E staining demonstrated NLC accumulation in murine AM in vivo with no signs of histopathological/biochemical changes. Bronchoalveolar lavage showed significantly low levels of LDH and total proteins (TP) for LNZ-NLCs highlighting their superior safety. Respirable microparticles embedding LNZ-NLCs ensured excellent aerosolization (MMAD 2 µm, FPF 93%) denoting perfect alveolar deposition. The developed inhalation therapy provided sustained LNZ release, mucus penetrability, potential safety in therapeutic doses, in vitro and in vivo macrophage targetability, and preferential deposition in the deep lung. Overall positive outcomes rely on reduced dose, dosing frequency, and per se superior safety circumventing systemic-associated life-threatening side effects. Graphical abstract.
Assuntos
Nanopartículas , Nanoestruturas , Tuberculose , Animais , Portadores de Fármacos/química , Macrófagos/metabolismo , Camundongos , Nanopartículas/química , Nanoestruturas/química , Tamanho da Partícula , Terapia Respiratória , Tuberculose/tratamento farmacológicoRESUMO
Intra-articular drug delivery represents a tempting strategy for local treatment of rheumatoid arthritis. Targeting drugs to inflamed joints bypasses systemic-related side effects. Albeit, rapid drug clearance and short joint residence limit intra-articular administration. Herein, injectable smart hydrogels comprising free/nanoencapsulated leflunomide (LEF) were developed. Nanostructured lipid carriers (NLCs), 200-300 nm, were coated with either chondroitin sulfate (CHS), hyaluronic acid (HA), or chitosan (CS) to provide joint targetability. Coated NLCs were incorporated in either hyaluronic/pluronic (HP) or chitosan/ß-glycerophosphate (CS/ßGP) hydrogels. Optimized systems ensured convenient gelation time (14-100 s), injectability (5-15 s), formulation-dependent mechanical strength, and extended LEF release up to 51 days. In vivo intra-articular injection in induced arthritis rat model revealed that rats treated with HA-coated NLCs showed the fastest recovery. Histopathological examination demonstrated perfect joint healing in case of HA-coated LEF-NLCs in CS/ßGP thermogel manifested as minor erosion of subchondral bone, improved intensity of extracellular matrix, cartilage thickness, and chondrocyte number. Both HA- and CHS-coated NLCs reduced TNF-α level 4-5-fold relative to positive control. The feat would be achieved via active targeting to CD44 receptors overexpressed in the articular tissue, limiting chondrocyte apoptosis together with innate synergistic targetability by promoting chondrocyte proliferation and neovascularization, inhibiting the production of pro-inflammatory cytokines, thus enhancing cartilaginous tissue repair.
Assuntos
Artrite Reumatoide , Quitosana , Animais , Artrite Reumatoide/tratamento farmacológico , Ácido Hialurônico/uso terapêutico , Hidrogéis/uso terapêutico , Leflunomida/uso terapêutico , RatosRESUMO
Oral treatment of rheumatoid arthritis (RA) with the immunomodulator, leflunomide (LEF), is associated with systemic side effects namely immunosuppression and hepatotoxicity. Herein, attempts to improve LEF therapeutic outcomes via nanostructured lipid carriers (NLCs) targeting inflamed rheumatic joints were executed. LEF-NLCs coated with either chondroitin sulphate (CHS) or chitosan (CS) were around 250â¯nm in size with negative or positive charge, respectively. Particle coating was evidenced by TEM and FTIR analysis. NLCs generally ensured sustained release profile up to 21â¯days, particularly extended in coated formulations. In vivo pharmacokinetic study of LEF suspension, uncoated NLCs, CHS- and CS-coated NLCs was carried out. Following oral administration in RA-induced rat model, joint diameter, paw inflammation, liver functions were measured, in addition to histological examination of liver, kidney and joints. Results revealed improved joint healing and reduced hepatotoxicity following treatment with nanoencapsulated LEF compared to LEF suspension, whereby CHS-NLCs ensued the highest Cmax, AUC and lowest TNF-α level. The dual potential of CHS to achieve active targeting to CD44-receptor and hence maximize LEF concentration at the target site in addition to its synergistic effect in joint healing endow promises for a competent oral nanosystem for targeted drug delivery to the joints.
Assuntos
Artrite Reumatoide/tratamento farmacológico , Portadores de Fármacos/administração & dosagem , Imunossupressores/administração & dosagem , Leflunomida/administração & dosagem , Lipídeos/administração & dosagem , Nanoestruturas/administração & dosagem , Administração Oral , Animais , Artrite Reumatoide/metabolismo , Artrite Reumatoide/patologia , Quitosana/administração & dosagem , Quitosana/química , Quitosana/farmacocinética , Sulfatos de Condroitina/administração & dosagem , Sulfatos de Condroitina/química , Sulfatos de Condroitina/farmacocinética , Portadores de Fármacos/química , Portadores de Fármacos/farmacocinética , Liberação Controlada de Fármacos , Imunossupressores/química , Imunossupressores/farmacocinética , Articulações/efeitos dos fármacos , Articulações/patologia , Leflunomida/química , Leflunomida/farmacocinética , Lipídeos/química , Lipídeos/farmacocinética , Masculino , Nanoestruturas/química , Ratos Sprague-DawleyRESUMO
With the non-selective vasodilating action, short half-life and first-pass metabolism of sildenafil (SC), local application in the lung for pulmonary arterial hypertension is of high demand. Although several nanosystems have been lately investigated, nanostructured lipid carriers (NLCs) give promises of potential safety, biodegradability and controlled drug release. In the current study, NLCs comprising either precirol, stearic acid or beeswax as solid lipid in presence of oleic acid as liquid lipid and PVA or poloxamer as emulsifier were prepared. Optimized NLCs (200-268â¯nm in size) were appraised versus SLNs both in vitro and in vivo. Precirol/PVA-based SLNs and NLCs ensued high entrapment efficiencies (EEâ¯>â¯95%) and controlled release behaviour over 6â¯h even though NLCs showed higher release profile. Stability studies at 4⯰C indicated potential colloidal and entrapment stability over 3â¯months. Interestingly, NLCs demonstrated efficient nebulization, low interaction with mucin and higher viability of A549 cells (3-fold increase in IC50 relative to SLNs) providing good aptitudes for pulmonary application. In vivo administration of free SC in rats revealed localized intra-alveolar bleeding, presumably related to excessive vasodilatation. Meanwhile, the nanoencapsulated drug confirmed normal lung parenchyma with minimal incidence of bleeding. Inspiring results highlight the potential of sildenafil-laden nanostructured lipid carriers as pulmonary drug delivery system.
Assuntos
Portadores de Fármacos/administração & dosagem , Hipertensão Pulmonar/tratamento farmacológico , Lipídeos/administração & dosagem , Nanoestruturas/administração & dosagem , Inibidores da Fosfodiesterase 5/administração & dosagem , Citrato de Sildenafila/administração & dosagem , Células A549 , Administração por Inalação , Animais , Sobrevivência Celular/efeitos dos fármacos , Preparações de Ação Retardada/administração & dosagem , Diglicerídeos/administração & dosagem , Humanos , Masculino , Álcool de Polivinil/administração & dosagem , Ratos Sprague-DawleyRESUMO
Alendronate (ALN) is a BCS III bone resorption inhibitor, with very poor oral bioavailability. Our approach is to develop a minimally invasive thermogelling system for prolonged local delivery of ALN. For this, different chitosan-based thermogels were developed and characterised in terms of gelation time, injectability, pH, viscosity and thermoreversibility. Chitosan/ß-glycerophosphate (CS/ßGP) hydrogel pursued temperature-dependent, thermoreversible gelation behaviour and was thus selected for drug loading. Increasing ALN concentration resulted in hydrogels with lower porosity and higher density. FTIR and DSC proved interaction between ALN, CS with ßGP. CS/ßGP hydrogel ensured controlled ALN release over 45-65 days depending on initial ALN loading. Freeze drying improved the shelf-life stability with minor impact on thermogelling character. In vivo injection of plain and ALN-loaded hydrogel in rats rapidly gelled 15 min post-injection. Based on histological examination, ALN-loaded thermogel showed less inflammatory response, faster proliferation and maturation of granulation tissue relative to plain thermogel. Hydrogels excised 21-days post-injection proved the biocompatibility and biodegradability of the system. The presented chitosan-based thermogel has significant positive attributes for site-specific, time-controlled, intra-articular delivery of ALN.
Assuntos
Alendronato/administração & dosagem , Conservadores da Densidade Óssea/administração & dosagem , Sistemas de Liberação de Medicamentos , Hidrogéis/química , Osteoporose/tratamento farmacológico , Alendronato/química , Alendronato/uso terapêutico , Animais , Conservadores da Densidade Óssea/química , Conservadores da Densidade Óssea/uso terapêutico , Varredura Diferencial de Calorimetria , Química Farmacêutica , Preparações de Ação Retardada , Glicerofosfatos/administração & dosagem , Injeções Subcutâneas , Microscopia Eletrônica de Varredura , Estudo de Prova de Conceito , Ratos , Espectroscopia de Infravermelho com Transformada de FourierRESUMO
Cationically modified poly(D,L-lactide-co-glycolide) (PLGA) nanoparticles have recently been introduced as novel carriers for DNA/RNA delivery. The colloidal characteristics of the nanoparticles--particle size and surface charge--are considered the most significant determinants in the cellular uptake and trafficking of the nanoparticles. Therefore, our aim was to introduce chitosan-coated PLGA nanoparticles, whose size and charge are tunable to adapt for a specific task. The results showed that biodegradable nanoparticles as small as 130 nm and adjustable surface charge can be tailored controlling the process parameters. As a proof of concept, the overall potential of these particulate carriers to bind the antisense oligonucleotides, 2'-O-methyl-RNA, and improve their cellular uptake was demonstrated. The study proved the efficacy of chitosan-coated PLGA nanoparticles as a flexible and efficient delivery system for antisense oligonucleotides to lung cancer cells.
Assuntos
Quitosana/química , Portadores de Fármacos/química , Ácido Láctico/química , Neoplasias Pulmonares/metabolismo , Nanopartículas/química , Ácido Poliglicólico/química , Polímeros/química , RNA Antissenso/farmacocinética , Transfecção/métodos , Linhagem Celular Tumoral , Materiais Revestidos Biocompatíveis , Cristalização/métodos , DNA/administração & dosagem , DNA/genética , DNA/farmacocinética , Composição de Medicamentos/métodos , Humanos , Neoplasias Pulmonares/genética , Teste de Materiais , Nanopartículas/ultraestrutura , Tamanho da Partícula , Copolímero de Ácido Poliláctico e Ácido Poliglicólico , RNA Antissenso/administração & dosagem , RNA Antissenso/genéticaRESUMO
The restless endeavors revealing the molecular pathways underlying many neurodegenerative diseases and brain tumors have paved the way for the introduction of the selective exogenous gene-based therapeutics. The implicated active biomolecules encompass mainly negatively-charged nucleic acids ranging from DNA, mRNA, non-coding RNAs (small-interfering RNA, siRNA, and microRNA, miRNA), to antisense oligonucleotides. They selectively interfere with the genes translational and/or transcriptional processes. Although many reviews previously addressed brain targeting, a thorough correlation between the molecular properties of these biomacromolecules, the nature of blood brain barrier (BBB) in the accompanying pathological condition, the intracellular targets, as well as the design of the delivery system which will transport the bioactive cargo to the target cells attempting efficient delivery to the active sites in the brain will be appraised. In this review, we will further discuss the tremendous advances in non-viral gene delivery nanosystems currently investigated (starting from self-assembled nanoplexes using cationic polymers or lipids and going through liposomes, aptamers, polymersomes, exosomes, dendrimers and nanoparticles). Unlike previous reviews on this topic, functionalization strategies of the nanocarriers promoting either surface receptor binding or intracellular targeting of the cranial cells will be highlighted, with special emphasis on tailoring smart nanomedicines according to the CNS disease condition. In addition, newly-developed evaluation approaches, cell culture models studying BBB permeability and manipulation of the barrier function of the brain via focused ultrasound will be addressed.
Assuntos
Barreira Hematoencefálica/metabolismo , Sistemas de Liberação de Medicamentos/métodos , Técnicas de Transferência de Genes , Nanomedicina/métodos , Nanopartículas/administração & dosagem , Ácidos Nucleicos/administração & dosagem , Animais , Encéfalo/irrigação sanguínea , Encéfalo/metabolismo , Terapia Genética/métodos , Humanos , Nanopartículas/química , Ácidos Nucleicos/genética , Ácidos Nucleicos/farmacocinéticaRESUMO
Phosphodiesterase type 5 (PDE-5) inhibitors - among which sildenafil citrate (SC) - play a primary role in the treatment of pulmonary hypertension (PH). Yet, SC can be only administered orally or parenterally with lot of risks. Targeted delivery of SC to the lungs via inhalation/nebulization is mandatory. In this study, solid lipid nanoparticles (SLNs) loaded with SC were prepared and characterized in terms of colloidal, morphological and thermal properties. The amount of drug loaded and its release behavior were estimated as a function of formulation variables. The potential of lipid nanocarriers to retain their properties following nebulization and autoclaving was investigated. In addition, toxicity aspects of plain and loaded SLNs on A549 cells were studied with respect to concentration. Spherical SLNs in the size range (100-250nm) were obtained. Particles ensured high encapsulation efficiency (88-100%) and sustained release of the payload over 24h. Cell-based viability experiments revealed a concentration-dependant toxicity for both plain and loaded SLNs recording an IC50 of 516 and 384µg/mL, respectively. Nebulization with jet nebulizer and sterilization via autoclaving affected neither the colloidal stability of SLNs nor the drug entrapment, proving their potential as pulmonary delivery system. Interaction of SLNs with mucin was a function of the emulsifier coating layer. Results yet seeking clinical evidence - might give promises of new therapy for PH of higher safety, better performance and higher patient compliance.
Assuntos
Portadores de Fármacos/química , Lipídeos/química , Nanopartículas/química , Inibidores da Fosfodiesterase 5/farmacocinética , Administração por Inalação , Sobrevivência Celular/efeitos dos fármacos , Células Cultivadas , Relação Dose-Resposta a Droga , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Hipertensão Pulmonar/tratamento farmacológico , Lipídeos/toxicidade , Mucinas/química , Nanopartículas/toxicidade , Nebulizadores e Vaporizadores , Tamanho da Partícula , Inibidores da Fosfodiesterase 5/administração & dosagem , Inibidores da Fosfodiesterase 5/química , Inibidores da Fosfodiesterase 5/toxicidade , Citrato de Sildenafila/administração & dosagem , Citrato de Sildenafila/química , Citrato de Sildenafila/farmacocinética , Citrato de Sildenafila/toxicidade , Solubilidade , EsterilizaçãoRESUMO
Myricetin - a natural flavonoid - has attracted a great interest due to its antioxidant and free-radical scavenging potential. However, its physicochemical instability critically impairs its dosage form design, evaluation and administration. In an attempt to protect from degradation, MYR was encapsulated into Gelucire-based solid lipid nanoparticles (SLNs). The impact of medium pH, processing temperature and different additives on the drug degradation either in free or nanoencapsulated form was assessed. MYR stability was further monitored in essential biorelevant fluids. Investigations have led to the recommendation that the presence of fat-soluble antioxidant is necessary during SLN preparation to protect the drug at high temperature. Meanwhile, physiological buffers as well as simulated fluids should be supplemented with stabilizers as tween 80 and Poloxamer 407, in addition to water-soluble antioxidant such as sodium sulfite. Interestingly, mucin-containing fluids are suggested to provide better protection to MYR, in contrast, cell culture media do not guarantee MYR stability. The degradation kinetics changed from 1st to 2nd order mechanism after MYR nanoencapsulation. In presence of the aforementioned additives, MYR-SLNs significantly reduced the drug degradation rate constant up to 300-folds and prolonged the half-life time up to 4500-folds compared to free MYR in physiological buffers (One-way ANOVA, p<0.05). As a proof of concept, in vitro release experiment in presence of phosphate buffer (pH7.4) supplemented with these additives ensured sustained release of MYR over >8h with no signs of degradation. The study emphasizes virtuous guidance regarding appropriate nanoencapsulation conditions and evaluation attributes ensuing MYR physicochemical stability.
Assuntos
Flavonoides/química , Nanopartículas/química , Composição de Medicamentos , Liberação Controlada de Fármacos , Estabilidade de Medicamentos , Concentração de Íons de Hidrogênio , Lipídeos , Concentração Osmolar , Saliva/químicaRESUMO
BACKGROUND: Aluminum phthalocyanine (AlPc) is an efficient second generation photosensitizer (PS) with high fluorescence ability. Its use in photodynamic therapy (PDT) is hampered by hydrophobicity and poor biodistribution. METHODS: AlPc was converted to a biocompatible nanostructure by incorporation into amphiphilic polyethylene glycol-polycaprolactone (PECL) copolymer nanoparticles, allowing efficient entrapment of the PS in the hydrophobic core, water dispersibility and biodistribution enhancement by PEG-induced surface characteristics. A series of synthesized PECL copolymers were used to prepare nanophotosensitizers with an average diameter of 66.5-99.1nm and encapsulation efficiency (EE%) of 66.4-78.0%. One formulation with favorable colloidal properties and relatively slow release over 7 days was selected for in vitro photophysical assessment and in vivo biodistribution studies in mice. RESULTS: The photophysical properties of AlPc were improved by encapsulating AlPc into PECL-NPs, which showed intense fluorescence emission at 687nm and no AlPc aggregation has been induced after entrapment into the nanoparticles. Biodistribution of AlPc loaded NPs (AlPc-NPs) and free AlPc drug in mice was monitored by in vivo whole body fluorescence imaging and ex vivo organ imaging, with in vivo imaging system (IVIS). Compared to a AlPc solution in aqueous TWEEN 80 (2 w/v%), the developed nanophotosensitizer showed targeted drug delivery to lungs, liver and spleen as monitored by the intrinsic fluorescence of AlPc at different time points (1h, 24h and 48h) post iv. administration. CONCLUSIONS: The AlPc-based copolymer nanoparticles developed offer potential as a single agent-multifunctional theranostic nanophotosensitizer for PDT coupled with imaging-guided drug delivery and biodistribution, and possibly also fluorescence diagnostics.
Assuntos
Indóis/farmacocinética , Microscopia de Fluorescência/métodos , Nanocápsulas/química , Compostos Organometálicos/farmacocinética , Fotoquimioterapia/métodos , Fármacos Fotossensibilizantes/farmacocinética , Nanomedicina Teranóstica/métodos , Animais , Difusão , Composição de Medicamentos/métodos , Indóis/síntese química , Indóis/uso terapêutico , Teste de Materiais , Taxa de Depuração Metabólica , Nanopartículas Metálicas/administração & dosagem , Nanopartículas Metálicas/química , Nanopartículas Metálicas/ultraestrutura , Camundongos , Camundongos Endogâmicos BALB C , Nanocápsulas/administração & dosagem , Nanocápsulas/ultraestrutura , Especificidade de Órgãos , Compostos Organometálicos/síntese química , Compostos Organometálicos/uso terapêutico , Tamanho da Partícula , Fármacos Fotossensibilizantes/síntese química , Fármacos Fotossensibilizantes/uso terapêutico , Poliésteres/química , Polietilenoglicóis/química , Tensoativos/síntese química , Tensoativos/farmacocinética , Tensoativos/uso terapêutico , Distribuição TecidualRESUMO
Whether mini-tablets (tablets, diameters ≤6mm) belong to single- or multiple-unit dosage forms is still questionable. Accordingly, Pharmacopoeial evaluation procedures for mini-tablets are lacking. In this study, the aforementioned points were discussed. Moreover, their potential for oral controlled delivery was assessed. The antidepressant venlafaxine hydrochloride (Vx), a highly soluble drug undergoing first pass effect, low bioavailability and short half-life was selected as a challenging payload. In an attempt to weigh up mini-tablets versus pellets as multiparticulate carriers, Vx-loaded mini-tablets were compared to formulated pellets of the same composition and the innovator Effexor(®)XR pellets. Formulations were prepared using various polymer hydrogels in the core and ethyl cellulose film coating with increasing thickness. Mini-tablets (diameter 2mm) showed extended Vx release (<60%, 8h). Indeed, release profiles comparable to Effexor(®)XR pellets were obtained. Remarkably higher coating thickness was required for pellets to provide equivalent retardation. Ethyl cellulose in the core ensured faster release due to polymer migration to the surface and pore formation in the coat. mini-tablets showed higher stability to pellets upon storage. Industrially speaking, mini-tablets proved to be superior to pellets in terms of manufacturing, product quality and economical aspects. Results point out the urgent need for standardized evaluation procedures for mini-tablets.
Assuntos
Antidepressivos/administração & dosagem , Comprimidos/química , Cloridrato de Venlafaxina/administração & dosagem , Celulose/análogos & derivados , Celulose/química , Química Farmacêutica , Preparações de Ação Retardada , Liberação Controlada de Fármacos , Excipientes/química , Dureza , Hidrogéis/química , Tamanho da Partícula , SolubilidadeRESUMO
This study aims at improving the buccal delivery of vitamin B6 (VB6) as a model highly water-soluble, low permeable vitamin. Two main strategies were combined; first VB6 was entrapped in liposomes, which were then formulated as mucoadhesive film. Both plain and VB6-loaded liposomes (LPs) containing Lipoid S100 and propylene glycol (â¼ 200 nm) were then incorporated into mucoadhesive film composed of SCMC and HPMC. Results showed prolonged release of VB6 (72.65%, T50% diss 105 min) after 6h from LP-film compared to control film containing free VB6 (96.37%, T50% diss 30 min). Mucoadhesion was assessed both ex vivo on chicken pouch and in vivo in human. Mucoadhesive force of 0.2N and residence time of 4.4h were recorded. Ex vivo permeation of VB6, across chicken pouch mucosa indicated increased permeation from LP-systems compared to corresponding controls. Interestingly, incorporation of the vesicles in mucoadhesive film reduced the flux by 36.89% relative to LP-dispersion. Meanwhile, both films provided faster initial permeation than the liquid forms. Correlating the cumulative percent permeated ex vivo with the cumulative percent released in vitro indicated that LPs retarded VB6 release but improved permeation. These promising results represent a step forward in the field of buccal delivery of water-soluble vitamins.