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For cancer therapy, paclitaxel (PX) possesses several limitations, including limited solubility and untargeted effects. Loading PX into nanoliposomes to enhance PX solubility and target their delivery as a drug delivery system has the potential to overcome these limitations. Over the other conventional method to prepare liposomes, a microfluidic system is used to formulate PX-loaded PEGylated liposomes. The impact of changing the flow rate ratio (FRR) between the aqueous and lipid phases on the particle size and polydispersity index (PDI) is investigated. Moreover, the effect of changing the polyethylene glycol (PEG) lipid ratio on the particle size, PDI, stability, encapsulation efficiency % (EE %), and release profile is studied. The physicochemical characteristics of the obtained formulation were analyzed by dynamic light scattering, FTIR spectroscopy, and AFM. This work aims to use microfluidic technology to produce PEGylated PX-loaded liposomes with a diameter of <200 nm, low PDI < 0.25 high homogeneity, and viable 28 day stability. The results show a significant impact of FRR and PEG lipid ratio on the empty liposomes' physicochemical characteristics. Among the prepared formulations, two formulations produce size-controlled, low PDI, and stable liposomes, which make them preferable for PX encapsulation. The average EE % was >90% for both formulations, and the variation in the PEG lipid ratio affected the EE % slightly; a high packing for PX was reported at different drug concentrations. A variation in the release profiles was notified for the different PEG lipid ratios.
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Liposomas , Paclitaxel , Paclitaxel/química , Liposomas/química , Microfluídica , Polietilenglicoles/química , Lípidos/química , Tamaño de la PartículaRESUMEN
Microfluidic technique has emerged as a promising tool for the production of stable and monodispersed nanoparticles (NPs). In particular, this work focuses on liposome production by microfluidics and on factors involved in determining liposome characteristics. Traditional fabrication techniques for microfluidic devices suffer from several disadvantages, such as multistep processing and expensive facilities. Three-dimensional printing (3DP) has been revolutionary for microfluidic device production, boasting facile and low-cost fabrication. In this study, microfluidic devices with innovative micromixing patterns were developed using fused deposition modelling (FDM) and liquid crystal display (LCD) printers. To date, this work is the first to study liposome production using LCD-printed microfluidic devices. The current study deals with 1,2-dimyristoyl-sn-glycero-3-phosphocholine (DMPC) liposomes with cholesterol (2:1) prepared using commercial and 3D-printed microfluidic devices. We evaluated the effect of microfluidic parameters, chip manufacturing, material, and channel design on liposomal formulation by analysing the size, PDI, and ζ-potential. Curcumin exhibits potent anticancer activity and it has been reported that curcumin-loaded liposomes formulated by microfluidics show enhanced encapsulation efficiency when compared with other reported systems. In this work, curcumal liposomes were produced using the developed microfluidic devices and particle sizing, ζ-potential, encapsulation efficiency, and in vitro release studies were performed at 37 °C.
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Curcumina/administración & dosificación , Sistemas de Liberación de Medicamentos , Liposomas , Microfluídica/instrumentación , Nanopartículas , Impresión TridimensionalRESUMEN
Implantable devices are versatile and promising drug delivery systems, and their advantages are well established. Of these advantages, long-acting drug delivery is perhaps the most valuable. Hydrophilic compounds are particularly difficult to deliver for prolonged times. This work investigates the use of poly(caprolactone) (PCL)-based implant coatings as a novel strategy to prolong the delivery of hydrophilic compounds from implantable devices that have been prepared by additive manufacturing (AM). Hollow implants were prepared from poly(lactic acid) (PLA) and poly(vinyl alcohol) (PVA) using fused filament fabrication (FFF) AM and subsequently coated in a PCL-based coating. Coatings were prepared by solution-casting mixtures of differing molecular weights of PCL and poly(ethylene glycol) (PEG). Increasing the proportion of low-molecular-weight PCL up to 60% in the formulations decreased the crystallinity by over 20%, melting temperature by over 4 °C, and water contact angle by over 40°, resulting in an increased degradation rate when compared to pure high-molecular-weight PCL. Addition of 30% PEG to the formulation increased the porosity of the formulation by over 50% when compared to an equivalent PCL-only formulation. These implants demonstrated in vitro release rates for hydrophilic model compounds (methylene blue and ibuprofen sodium) ranging from 0.01 to 34.09 mg/day, depending on the drug used. The versatility of the devices produced in this work and the range of release rates achievable show great potential. Implants could be specifically developed in order to match the specific release rate required for a number of drugs for a wide range of conditions.
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Preparaciones de Acción Retardada/química , Preparaciones Farmacéuticas/química , Poliésteres/química , Implantes Absorbibles , Sistemas de Liberación de Medicamentos/métodos , Interacciones Hidrofóbicas e Hidrofílicas , Polietilenglicoles/química , Alcohol Polivinílico/química , Impresión TridimensionalRESUMEN
The main aim of the research was to synthesize amphiphilic cyclodextrin (AMCD) by substituting C12 alkyl chain to a ß-cyclodextrin (ßCD) in a single step and to study its self-assembly in an aqueous medium. The drug delivery application of the AMCD was also evaluated by encapsulating tamoxifen citrate as a model hydrophobic drug. AMCD was able to self-assemble in aqueous media, forming nanovesicles of size < 200 nm, capable of encapsulating tamoxifen citrate (TMX). Molecular docking and MD simulation studies revealed the interaction between TMX and AMCD which formed a stable complex. TEM and AFM studies showed that nanovesicles were perfectly spherical having a smooth surface and a theoretical AMCD bilayer thickness of ~ 7.2 nm as observed from SANS studies. XRD and DSC studies revealed that TMX was amorphized and molecularly dispersed in AMCD bilayer which was released slowly following Fickian diffusion. AMCD has excellent hemocompatibility as opposed to ßCD and no genotoxicity. IC50 of TMX against MCF-7 cell lines was significantly reduced from 11.43 to 7.96 µg/ml after encapsulation in nanovesicle because of nanovesicles being endocytosed by the MCF-7 cells. AMCD was well tolerated by IV route at a dose of > 2000 mg/kg in rats. Pharmacokinetic profile of TMX after encapsulation was improved giving 3-fold higher AUC; extended mean residence time is improving chances of nanovesicle to extravasate in tumor via EPR effect.
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Ciclodextrinas/administración & dosificación , Ciclodextrinas/síntesis química , Sistemas de Liberación de Medicamentos/métodos , Tamoxifeno/administración & dosificación , Tamoxifeno/síntesis química , Administración Oral , Animales , Supervivencia Celular/efectos de los fármacos , Supervivencia Celular/fisiología , Portadores de Fármacos/administración & dosificación , Portadores de Fármacos/síntesis química , Femenino , Humanos , Interacciones Hidrofóbicas e Hidrofílicas , Células MCF-7 , Masculino , Ratones , Simulación del Acoplamiento Molecular/métodos , Ratas , Ratas WistarRESUMEN
The fast development in materials science has resulted in the emergence of new pharmaceutical materials with superior physical and mechanical properties. Low-substituted hydroxypropyl cellulose is an ether derivative of cellulose and is praised for its multi-functionality as a binder, disintegrant, film coating agent and as a suitable material for medical dressings. Nevertheless, very little is known about the compaction behaviour of this polymer. The aim of the current study was to evaluate the compaction and disintegration behaviour of four grades of L-HPC namely; LH32, LH21, LH11, and LHB1. The macrometric properties of the four powders were studied and the compaction behaviour was evaluated using the out-of-die method. LH11 and LH22 showed poor flow properties as the powders were dominated by fibrous particles with high aspect ratios, which reduced the powder flow. LH32 showed a weak compressibility profile and demonstrated a large elastic region, making it harder for this polymer to deform plastically. These findings are supported by AFM which revealed the high roughness of LH32 powder (100.09 ± 18.84 nm), resulting in small area of contact, but promoting mechanical interlocking. On the contrary, LH21 and LH11 powders had smooth surfaces which enabled larger contact area and higher adhesion forces of 21.01 ± 11.35 nN and 9.50 ± 5.78 nN, respectively. This promoted bond formation during compression as LH21 and LH11 powders had low strength yield.
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Celulosa/análogos & derivados , Composición de Medicamentos , Celulosa/química , Fuerza Compresiva , Composición de Medicamentos/métodos , Elasticidad , Excipientes/química , Fenómenos Mecánicos , Porosidad , Polvos , Solubilidad , ComprimidosRESUMEN
PURPOSE: The present study reports a novel conjugate of gemcitabine (GEM) with bovine serum albumin (BSA) and thereof nanoparticles (GEM-BSA NPs) to potentiate the therapeutic efficacy by altering physicochemical properties, improving cellular uptake and stability of GEM. METHODS: The synthesized GEM-BSA conjugate was extensively characterized by NMR, FTIR, MALDI-TOF and elemental analysis. Conjugation mediated changes in structural conformation and physicochemical properties were analysed by fluorescence, Raman and CD spectroscopy, DSC and contact angle analysis. Further, BSA nanoparticles were developed from BSA-GEM conjugate and extensively evaluated against in-vitro pancreatic cancer cell lines to explore cellular uptake pathways and therapeutic efficacy. RESULTS: Various characterization techniques confirmed covalent conjugation of GEM with BSA. GEM-BSA conjugate was then transformed into NPs via high pressure homogenization technique with particle size 147.2 ± 7.3, PDI 0.16 ± 0.06 and ZP -19.2 ± 1.4. The morphological analysis by SEM and AFM revealed the formation of smooth surface spherical nanoparticles. Cellular uptake studies in MIA PaCa-2 (GEM sensitive) and PANC-1 (GEM resistant) pancreatic cell lines confirmed energy dependent clathrin internalization/endocytosis as a primary mechanism of NPs uptake. In-vitro cytotoxicity studies confirmed the hNTs independent transport of GEM in MIA PaCa-2 and PANC-1 cells. Moreover, DNA damage and annexin-V assay revealed significantly higher apoptosis level in case of cells treated with GEM-BSA NPs as compared to free GEM. CONCLUSIONS: GEM-BSA NPs were found to potentiate the therapeutic efficacy by altering physicochemical properties, improving cellular uptake and stability of GEM and thus demonstrated promising therapeutic potential over free drug. Graphical Abstract á .
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Antineoplásicos/química , Desoxicitidina/análogos & derivados , Nanopartículas/química , Neoplasias Pancreáticas/tratamiento farmacológico , Albúmina Sérica Bovina/química , Animales , Antineoplásicos/farmacología , Apoptosis , Bovinos , Línea Celular Tumoral , Supervivencia Celular , Desoxicitidina/química , Desoxicitidina/farmacología , Liberación de Fármacos , Resistencia a Antineoplásicos , Humanos , Tamaño de la Partícula , Propiedades de Superficie , GemcitabinaRESUMEN
We report on-demand formation of emulsions stabilised by interfacial nanoscale networks. These are formed through biocatalytic dephosphorylation and self-assembly of Fmoc(9-fluorenylmethoxycarbonyl)dipeptide amphiphiles in aqueous/organic mixtures. This is achieved by using alkaline phosphatase which transforms surfactant-like phosphorylated precursors into self-assembling aromatic peptide amphiphiles (Fmoc-tyrosine-leucine, Fmoc-YL) that form nanofibrous networks. In biphasic organic/aqueous systems, these networks form preferentially at the interface thus providing a means of emulsion stabilisation. We demonstrate on-demand emulsification by enzyme addition, even after storage of the biphasic mixture for several weeks. Experimental (Fluorescence, FTIR spectroscopy, fluorescence microscopy, electron microscopy, atomic force microscopy) and computational techniques (atomistic molecular dynamics) are used to characterise the interfacial self-assembly process.
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Fosfatasa Alcalina/metabolismo , Nanofibras/química , Fosfatasa Alcalina/química , Dipéptidos/química , Emulsiones , Fluorenos/química , Simulación de Dinámica Molecular , Conformación ProteicaRESUMEN
Vaccines administered parenterally have been developed against gonadotrophin-releasing hormone (GnRH) for anti-fertility and anti-cancer purposes. The aim of this study was to demonstrate whether mucosal delivery using GnRH immunogens entrapped in lipid nanoparticles (LNP) could induce anti-GnRH antibody titers. Immunogens consisting of KLH (keyhole limpet hemocyanin) conjugated to either GnRH-I or GnRH-III analogues were entrapped in LNP. Loaded non-ionic surfactant vesicles (NISVs) were administered subcutaneously, while nasal delivery was achieved using NISV in xanthan gum and oral delivery using NISV containing deoxycholate (bilosomes). NISV and bilosomes had similar properties: they were spherical, in the nanometre size range, with a slightly negative zeta potential and surface properties that changed with protein loading and inclusion of xanthan gum. Following immunization in female BALB/c mice, systemic antibody responses were similar for both GnRH-I and GnRH-III immunization. Only nasal delivery proved to be successful in terms of producing systemic and mucosal antibodies. FROM THE CLINICAL EDITOR: The main research question addressed in this study was whether mucosal delivery using gonadotrophin-releasing hormone immunogens entrapped in lipid nanoparticles could induce anti-GnRH antibody titers. Only nasal delivery proved to be successful in terms of producing systemic and mucosal antibodies with this approach.
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Formación de Anticuerpos/inmunología , Hormona Liberadora de Gonadotropina/química , Hormona Liberadora de Gonadotropina/inmunología , Nanopartículas/administración & dosificación , Nanopartículas/química , Administración a través de la Mucosa , Animales , Femenino , Humanos , Ratones , Ratones Endogámicos BALB C , Microscopía de Fuerza Atómica , Ácido Pirrolidona Carboxílico/análogos & derivados , Ácido Pirrolidona Carboxílico/química , Ácido Pirrolidona Carboxílico/inmunologíaRESUMEN
This review provides an in-depth exploration of electrospinning techniques employed to produce micro- or nanofibres of biopharmaceuticals using polymeric solutions or melts with high-voltage electricity. Distinct from prior reviews, the current work narrows its focus on the recent developments and advanced applications in biopharmaceutical formulations. It begins with an overview of electrospinning principles, covering both solution and melt modes. Various methods for incorporating biopharmaceuticals into electrospun fibres, such as surface adsorption, blending, emulsion, co-axial, and high-throughput electrospinning, are elaborated. The review also surveys a wide array of biopharmaceuticals formulated through electrospinning, thereby identifying both opportunities and challenges in this emerging field. Moreover, it outlines the analytical techniques for characterizing electrospun fibres and discusses the legal and regulatory requirements for their production. This work aims to offer valuable insights into the evolving realm of electrospun biopharmaceutical delivery systems.
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Productos Biológicos , Nanofibras , Polímeros , Electricidad , Composición de MedicamentosRESUMEN
The inherent flexibility of elastic liposomes (EL) allows them to penetrate the small skin pores and reach the dermal region, making them an optimum candidate for topical drug delivery. Loading chemotherapy in ELs could improve chemotherapy's topical delivery and localise its effect on skin carcinogenic tissues. Chemotherapy-loaded EL can overcome the limitations of conventional administration of chemotherapies and control the distribution to specific areas of the skin. In the current studies, Paclitaxel was utilised to develop Paclitaxel-loaded EL. As an alternative to the conventional manufacturing methods of EL, this study is one of the novel investigations utilising microfluidic systems to examine the potential to enhance and optimise the quality of Els by the microfluidics method. The primary aim was to achieve EL with a size of < 200 nm, high homogeneity, high encapsulation efficiency, and good stability. A phospholipid (DOPC) combined with neutral and anionic edge activators (Tween 80 and sodium taurocholate hydrate) at various lipid-to-edge activator ratios, was used for the manufacturing of the ELs. A preliminary study was performed to study the size, polydispersity (PDI), and stability to determine the optimum microfluidic parameters and lipid-to-edge activator for paclitaxel encapsulation. Furthermore, physiochemical characterisation was performed on the optimised Paclitaxel-loaded EL using a variety of methods, including Dynamic Light Scattering, Fourier Transform Infrared Spectroscopy, Atomic force microscopy, elasticity, encapsulation efficiency, and In vitro release. The results reveal the microfluidics' significant impact in enhancing the EL characteristics of EL, especially small and controllable size, Low PDI, and high encapsulation efficiency. Moreover, the edge activator type and concentration highly affect the EL characteristics. The Tween 80 formulations with optimised concentration provide the most suitable size and higher encapsulation efficiency. The release profile of the formulations showed more immediate release from the EL with higher edge activator concentration and a higher % of the released dug from the Tween 80 formulations.
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Developing drug delivery systems (DDSs) is one of the approaches used to improve cancer treatment, with the main goal of loading cancer drugs into a carrier targeting a specific organ and avoiding the distribution to healthy tissues. Nanoparticles (NPs) have been shown to be one of the optimum carriers that can be used as DDSs. Lipid-based NPs, such as liposomes, have been investigated in the current study due to their low toxicity and ability to carry hydrophilic and hydrophobic molecules. In the current studies, conventional liposomes composed of DPPC, and cholesterol and PEGylated liposomes composed of DPPC, cholesterol, and DSPE-PEG2000 are manufactured and loaded with Carboplatin. The study focused on investigating and comparing the impact of modifying the carboplatin-loaded liposomes with different concentrations of DSPE-PEG2000 on the NP diameter, polydispersity, ζ-potential, encapsulation efficiency (EE%), and drug release. The hydrodynamic microfluidic system was used to investigate any possible improvement in the EE% over other conventional methods. The results showed the microfluidic system's promising effect in enhancing the EE% of the Carboplatin. Moreover, the results showed a smaller diameter and higher stability of the PEGylated liposome. However, conventional liposomes represent better homogeneity and higher encapsulation efficiency for hydrophilic molecules.
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Liposomas , Microfluídica , Fosfatidiletanolaminas , Liposomas/química , Carboplatino , Polietilenglicoles/química , Colesterol/químicaRESUMEN
BACKGROUND: Pain is characterized as a major symptom induced by tissue damage occurring from surgical procedures, whose potency is being experienced subjectively, while current pain relief strategies are not always efficient in providing individualized treatment. 3D printed implantable devices hold the potential to offer a precise and customized medicinal approach, targeting both tissue engineering and drug delivery. RESEARCH DESIGN AND METHODS: Polycaprolactone (PCL) and PCL - chitosan (CS) composite scaffolds loaded with procaine (PRC) were fabricated by bioprinting. Geometrical features including dimensions, pattern, and infill of the scaffolds were mathematically optimized and digitally determined, aiming at developing structurally uniform 3D printed models. Printability studies based on thermal imaging of the bioprinting system were performed, and physicochemical, surface, and mechanical attributes of the extruded scaffolds were evaluated. The release rate of PRC was examined at different time intervals up to 1 week. RESULTS: Physicochemical stability and mechanical integrity of the scaffolds were studied, while in vitro drug release studies revealed that CS contributes to the sustained release dynamic of PRC. CONCLUSIONS: The printing extrusion process was capable of developing implantable devices for a local and sustained delivery of PRC as a 7-day adjuvant regimen in post-operative pain management.
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The utilization of 3D printing- digital light processing (DLP) technique, for the direct fabrication of microneedles encounters the problem of drug solubility in printing resin, especially if it is predominantly composed of water. The possible solution how to ensure ideal belonging of drug and water-based printing resin is its pre-formulation in nanosuspension such as nanocrystals. This study investigates the feasibility of this approach on a resin containing nanocrystals of imiquimod (IMQ), an active used in (pre)cancerous skin conditions, well known for its problematic solubility and bioavailability. The resin blend of polyethylene glycol diacrylate and N-vinylpyrrolidone, and lithium phenyl-2,4,6-trimethylbenzoylphosphinate as a photoinitiator, was used, mixed with IMQ nanocrystals in water. The final microneedle-patches had 36 cylindrical microneedles arranged in a square grid, measuring approximately 600 µm in height and 500 µm in diameter. They contained 5wt% IMQ, which is equivalent to a commercially available cream. The homogeneity of IMQ distribution in the matrix was higher for nanocrystals compared to usual crystalline form. The release of IMQ from the patches was determined ex vivo in natural skin and revealed a 48% increase in efficacy for nanocrystal formulations compared to the crystalline form of IMQ.
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Three-dimensional printing (3DP) is an emerging technology, offering the possibility for the development of dose-customized, effective, and safe solid oral dosage forms (SODFs). Although 3DP has great potential, it does come with certain limitations, and the traditional drug manufacturing platforms remain the industry standard. The consensus appears to be that 3DP technology is expected to benefit personalized medicine the most, but that it is unlikely to replace conventional manufacturing for mass production. The 3DP method, on the other hand, could prove well-suited for producing small batches as an adaptive manufacturing technique for enabling adaptive clinical trial design for early clinical studies. The purpose of this review is to discuss recent advancements in 3DP technologies for SODFs and to focus on the applications for SODFs in the early clinical development stages, including a discussion of current regulatory challenges and quality controls.
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Medicina de Precisión , Impresión Tridimensional , Medicina de Precisión/métodos , Industrias , Control de Calidad , Preparaciones Farmacéuticas , Tecnología Farmacéutica/métodos , Formas de DosificaciónRESUMEN
Vat photopolymerisation (VP) three-dimensional printing (3DP) has attracted great attention in many different fields, such as electronics, pharmaceuticals, biomedical devices and tissue engineering. Due to the low availability of biocompatible photocurable resins, its application in the healthcare sector is still limited. In this work, we formulate photocurable resins based on urethane dimethacrylate (UDMA) combined with three different difunctional methacrylic diluents named ethylene glycol dimethacrylate (EGDMA), di(ethylene glycol) dimethacrylate (DEGDMA) or tri(ethylene glycol) dimethacrylate (TEGDMA). The resins were tested for viscosity, thermal behaviour and printability. After printing, the 3D printed specimens were measured with a digital calliper in order to investigate their accuracy to the digital model and tested with FT-IR, TGA and DSC. Their mechanical properties, contact angle, water sorption and biocompatibility were also evaluated. The photopolymerizable formulations investigated in this work achieved promising properties so as to be suitable for tissue engineering and other biomedical applications.
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Resinas Compuestas , Estereolitografía , Resinas Compuestas/química , Espectroscopía Infrarroja por Transformada de Fourier , Impresión TridimensionalRESUMEN
The production of solid lipid nanoparticles (SLNs) is challenging, especially when considering the incorporation of biologics. A novel in-house method of microfluidic production of biologic-encapsulated SLNs is proposed, using a variety of base materials for formulation to help overcome the barriers presented during manufacture and administration. Trypsin is used as a model drug for hydrophilic encapsulation whilst testosterone is employed as a positive non-biologic lipophilic control active pharmaceutical ingredient. Particle sizes obtained ranged from 160 to 320 nm, and a lead formulation has been identified from the combinations assayed, allowing for high encapsulation efficiencies (47-90%, respectively) of both the large hydrophilic and the small hydrophobic active pharmaceutical ingredients (APIs). Drug release profiles were analysed in vitro to provide useful insight into sustained kinetics, providing data towards future in vivo studies, which displayed a slow prolonged release for testosterone and a quicker burst release for trypsin. The study represents a large leap forward in the field of SLN production, especially in the field of difficult-to-encapsulate molecules, and the technique also benefits from being more environmentally sustainable due to the use of microfluidics.
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Microfluídica , Nanopartículas , Lípidos/química , Tripsina , Nanopartículas/química , Esteroides , Testosterona , Tamaño de la Partícula , Portadores de Fármacos/químicaRESUMEN
Timolol maleate (TML) is a beta-blocker drug that is commonly used to lower the intraocular pressure in glaucoma. This study focused on using a 3D printing (3DP) method for the manufacturing of an ocular, implantable, sustained-release drug delivery system (DDS). Polycaprolactone (PCL), and PCL with 5 or 10% TML implants were manufactured using a one-step 3DP process. Their physicochemical characteristics were analysed using light microscopy, scanning electronic microscopy (SEM), differential scanning calorimetry (DSC) / thermal gravimetric analysis (TGA), and Fourier-transform infrared spectroscopy (FTIR). The in vitro drug release was evaluated by UV-spectrophotometry. Finally, the effect of the implants on cell viability in human trabecular meshwork cells was assessed. All the implants showed a smooth surface. Thermal analysis demonstrated that the implants remained thermally stable at the temperatures used for the printing, and FTIR studies showed that there were no significant interactions between PCL and TML. Both concentrations (5 & 10%) of TML achieved sustained release from the implants over the 8-week study period. All implants were non-cytotoxic to human trabecular cells. This study shows proof of concept that 3DP can be used to print biocompatible and personalised ocular implantable sustained-release DDSs for the treatment of glaucoma.
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Diabetic complications present throughout a wide range of body tissues, however one of the most widely recognised complications remains to be chronic diabetic wounds. Current treatment options largely rely on standard wound treatment routines which provide no promotion of wound healing mechanisms at different physiological stages of repair. Recently materials produced using novel additive manufacturing techniques have been receiving attention for applications in wound care and tissue repair. Additive manufacturing techniques have recently been used in the interest of targeted drug delivery and production of novel materials resembling characteristics of native tissues. The potential to exploit these highly tailorable manufacturing techniques for the design of novel wound care remedies is highly desirable. In the present study two additive manufacturing techniques are combined to produce a scaffold for the treatment of diabetic wounds. The combination of microfluidic manufacturing of an antimicrobial liposome (LP) formulation and a coaxial electrospinning method incorporating both antimicrobial and proangiogenic factors allowed dual delivery of therapeutics to target both infection and lack of vascularisation at wound sites. The coaxial fibres comprised of a polyvinyl alcohol (PVA) core containing vascular endothelial growth factor (VEGF) and a poly (l-lactide-co-ε-caprolactone) (PLCL) shell blended with amoxicillin (Amox). Additionally, a liposomal formulation was produced to incorporate Amox and adhered to the surface of fibres loaded with Amox and VEGF. The liposomal loading provided the potential to deliver a much higher, more clinically relevant dose of Amox without detrimentally changing the mechanical properties of the material. The growth factor release was sustained up to 7-days in vitro. The therapeutic effect of the antibiotic loading was analysed using a disk diffusion method with a significant increase in zone diameter following LP adhesion, proving the full scaffold system had improved efficacy against both Gram-positive and Gram-negative strains. Additionally, the dual-loaded scaffolds show enhanced potential for supporting vascular growth in vitro, as demonstrated via a viability assay and tubule formation studies. Results showed a significant increase in the average total number of tubes from 10 in control samples to 77 in samples fully-loaded with Amox and VEGF.
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Antiinfecciosos , Diabetes Mellitus , Humanos , Amoxicilina/farmacología , Amoxicilina/uso terapéutico , Factor A de Crecimiento Endotelial Vascular , LiposomasRESUMEN
With an increasing concern of global antimicrobial resistance, the efforts to improve the formulation of a narrowing library of therapeutic antibiotics must be confronted. The liposomal encapsulation of antibiotics using a novel and sustainable microfluidic method has been employed in this study to address this pressing issue, via a targeted, lower-dose medical approach. The study focusses upon microfluidic parameter optimisation, formulation stability, cytotoxicity, and future applications. Particle sizes of circa. 130 nm, with viable short-term (28-day) physical stability were obtained, using two different non-cytotoxic liposomal formulations, both of which displayed suitable antibacterial efficacy. The microfluidic method allowed for high encapsulation efficiencies (≈77 %) and the subsequent in vitro release profile suggested high limits of antibiotic dissociation from the nanovessels, achieving 90% release within 72 h. In addition to the experimental data, the growing use of poly(ethylene) glycol (PEG) within lipid-based formulations is discussed in relation to anti-PEG antibodies, highlighting the key pharmacological differences between PEGylated and non-PEGylated formulations and their respective advantages and drawbacks. It's surmised that in the case of the formulations used in this study, the addition of PEG upon the liposomal membrane would still be a beneficial feature to possess owing to beneficial features such as stability, antibiotic efficacy and the capacity to further modify the liposomal membrane.
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Amoxicilina , Microfluídica , Liposomas , Antibacterianos , PolietilenglicolesRESUMEN
Sirolimus has recently been introduced as a therapeutic agent for breast and prostate cancer. In the current study, conventional and Stealth liposomes were used as carriers for the encapsulation of sirolimus. The physicochemical characteristics of the sirolimus liposome nanoparticles were investigated including the particle size, zeta potential, stability and membrane integrity. In addition atomic force microscopy was used to study the morphology, surface roughness and mechanical properties such as elastic modulus deformation and deformation. Sirolimus encapsulation in Stealth liposomes showed a high degree of deformation and lower packing density especially for dipalmitoyl-phosphatidylcholine (DPPC) Stealth liposomes compared to unloaded. Similar results were obtained by differential scanning calorimetry (DSC) studies; sirolimus loaded liposomes were found to result in a distorted state of the bilayer. X-ray photon electron (XPS) analysis revealed a uniform distribution of sirolimus in multilamellar DPPC Stealth liposomes compared to a nonuniform, greater outer layer lamellar distribution in distearoylphosphatidylcholine (DSPC) Stealth liposomes.