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1.
Encapsulation, protection, and delivery of bioactive proteins and peptides using nanoparticle and microparticle systems: A review.
McClements, DJ
Advances in colloid and interface science. 2018;:1-22
Abstract
There are many examples of bioactive proteins and peptides that would benefit from oral delivery through functional foods, supplements, or medical foods, including hormones, enzymes, antimicrobials, vaccines, and ACE inhibitors. However, many of these bioactive proteins are highly susceptible to denaturation, aggregation or hydrolysis within commercial products or inside the human gastrointestinal tract (GIT). Moreover, many bioactive proteins have poor absorption characteristics within the GIT. Colloidal systems, which contain nanoparticles or microparticles, can be designed to encapsulate, retain, protect, and deliver bioactive proteins. For instance, a bioactive protein may have to remain encapsulated and stable during storage and passage through the mouth and stomach, but then be released within the small intestine where it can be absorbed. This article reviews the application of food-grade colloidal systems for oral delivery of bioactive proteins, including microemulsions, emulsions, nanoemulsions, solid lipid nanoparticles, multiple emulsions, liposomes, and microgels. It also provides a critical assessment of the characteristics of colloidal particles that impact the effectiveness of protein delivery systems, such as particle composition, size, permeability, interfacial properties, and stability. This information should be useful for the rational design of medical foods, functional foods, and supplements for effective oral delivery of bioactive proteins.
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2.
Recent advances in oral delivery of biologics: nanomedicine and physical modes of delivery.
Vllasaliu, D, Thanou, M, Stolnik, S, Fowler, R
Expert opinion on drug delivery. 2018;(8):759-770
Abstract
INTRODUCTION Research into oral delivery of biologics has a long and rich history but has not produced technologies used in the clinic. The area has evolved in terms of strategies to promote oral biologics delivery from early chemical absorption enhancers to nanomedicine to devices. Continued activity in this area is justifiable considering the remarkable proliferation of biologics. AREAS COVERED The article discusses some physiological barriers to oral delivery of biologics, with a special focus on less characterized barriers such as the basement membrane. Recent progress in oral delivery of biologics via nanomedicine is subsequently covered. Finally, the emerging field of device-mediated gastrointestinal delivery of biotherapeutics is discussed EXPERT OPINION Oral delivery of biologics is considered a 'panacea' in drug delivery. Almost century-old approaches of utilizing chemical absorption enhancers have not produced clinically translated technologies. Nanomedicine for oral biologics delivery has demonstrated potential, but the field is relatively new, and technologies have not progressed to the clinic. Device-mediated oral biologics delivery (e.g. ultrasound or microneedles) is in its infancy. However, this space is likely to intensify owing to advances in electronics and materials, as well as the challenges and history related to clinical translation of alternative approaches.
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3.
A Novel Curcumin-Galactomannoside Complex Delivery System Improves Hepatic Function Markers in Chronic Alcoholics: A Double-Blinded, randomized, Placebo-Controlled Study.
T Krishnareddy, N, Thomas, JV, Nair, SS, N Mulakal, J, Maliakel, BP, Krishnakumar, IM
BioMed research international. 2018;:9159281
Abstract
Considering the recent interest in free (unconjugated) curcuminoids delivery, the present study investigated the efficacy of a novel food-grade free-curcuminoids delivery system (curcumin-galactomannoside complex; CGM) in improving the hepatic function markers (inflammation and oxidative stress) in chronic alcoholics. The double-blinded, placebo-controlled study randomized 48 subjects with elevated serum transaminases and gamma-glutamyl transferase (GGT) levels, who were allocated to two groups (n=24) and to receive either placebo or CGM at (250 mg × 2)/day for 8 weeks. While liver function markers (transaminases and GGT) in the placebo group showed an increase (~ 9.5%), CGM group indicated a significant decrease in transaminases (31%) and GGT (29%) from the baseline levels. The beneficial effect of CGM was also clear from the significant increase (p <0.001) in endogenous antioxidants (GSH, SOD, and GPx) and decrease in inflammatory markers (IL-6 and CRP) levels (p <0.001) as compared to both the baseline and placebo group. To summarize, the nutritional intervention of CGM-curcumin was found to offer a significant hepatoprotective effect to attenuate the alcohol induced alterations to hepatic function markers. The Indian Medical Council and Drug Controller General of India approved Clinical Trial Registry No. CTRI/2018/03/012385.
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4.
Oral Insulin: Myth or Reality.
Kumar, V, Choudhry, I, Namdev, A, Mishra, S, Soni, S, Hurkat, P, Jain, A, Jain, D
Current diabetes reviews. 2018;(6):497-508
Abstract
BACKGROUND Diabetes Mellitus (DM) is a disorder of glucose metabolism marked by hyperglycemia, glycosuria, hyperlipidemia, negative nitrogen balance and ketonaemia. DM is a major healthcare problems today and its treatment costs billions of dollars worldwide annually. The cases of diabetes have increased rapidly in recent years throughout the world. Currently, for the management of Type-1 Diabetes Mellitus (TIDM), Multiple Daily Insulin (MDI) injections is the most popular treatment. Oral administration of insulin is the most suitable and attractive as compared to subcutaneous route but unfortunately cannot be utilized for the administration of peptides and proteins due to poor epithelial permeability and enzymatic degradation within the gastrointestinal tract. Since many years, extensive research has been carried out to explore the potential ways of insulin administration based on novel methods such as liposome, microsphere, nanoparticle, mouth dissolving strips, sprays exploiting oral and pulmonary route. These next generation efficient therapies for T1DM may help to improve the quality of life of diabetic patients especially in Insulin Dependent Diabetes Mellitus (IDDM). CONCLUSION This review emphasizes on the most recent progress made in the development of oral insulin delivery formulations, and focuses on key lessons and implications from studies undertaken till date with the oral insulin formulations. Further, this review analyzes effectiveness of the advancements, applications and limitations of the technologies in delivering insulin to the targeted site through oral administration.
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5.
Targeting postprandial glycaemia in children with diabetes: Opportunities and challenges.
Geyer, MC, Rayner, CK, Horowitz, M, Couper, JJ
Diabetes, obesity & metabolism. 2018;(4):766-774
Abstract
Postprandial glycaemia makes a substantial contribution to overall glycaemic control in diabetes, particularly in patients whose preprandial glycaemia is relatively well controlled and glycated haemoglobin (HbA1c) only modestly elevated. Our review addresses the determinants of postprandial glycaemia and how it may be targeted therapeutically in children with diabetes. Postprandial glycaemia is influenced by preprandial glycaemia, macronutrients and their absorption, insulin delivery and sensitivity, the action of the enteroendocrine system, and the rate of gastric emptying. Contemporary continuous glucose monitoring systems reveal patterns of post prandial glycaemia and allow management to be guided more precisely. Delays in blood glucose determination, insulin delivery and its absorption remain challenges in the rapidly evolving closed loop continuous subcutaneous insulin and glucagon delivery systems developed for children with type 1 diabetes. Augmentation of the incretin system through nutritional preloads or incretin mimetics targets postprandial glycaemia by slowing gastric emptying as well as insulinotropic and glucagonostatic effects. These treatments are of particular relevance to children with type 2 diabetes. Following the development of targeted therapies in adults, postprandial blood glucose control will now be increasingly targeted in the treatment of diabetes in children.
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6.
Sustained Release of Poorly Water-Soluble Drug from Hydrophilic Polymeric Film Sandwiched Between Hydrophobic Layers.
Kevadiya, BD, Zhang, L, Davé, RN
AAPS PharmSciTech. 2018;(6):2572-2584
Abstract
This proof-of-concept study explores the feasibility of using a drug-loaded hydrophilic polymeric layer sandwiched between two hydrophobic layers for improving film drug load while achieving sustained release of poorly water-soluble drug. Such films having total thickness in range ~ 146-250 μm were prepared by slurry-based casting using hydrophilic hydroxypropyl methylcellulose (HPMC) as matrix layer containing fenofibrate (FNB) as the model drug, encased between two very thin rate-limiting layers of 10 μm each of hydrophobic poly-ɛ-caprolactone (PCL). Film precursor slurry consisted of HPMC with plasticizer and water along with micronized FNB powders, which were dry-coated with hydrophilic silica. Characterization techniques demonstrated the presence of homogeneously dispersed crystalline FNB in films. The films are very thin and hence two-dimensional; hence, average drug load per unit area in range ~ 5 to ~ 9 mg/cm2 could be achieved by altering the thickness of the drug matrix layer. Drug amount and drug content uniformity were measured through assay of ten circular samples ~ 0.712 cm2 in area punched out using a circular-shaped punch tool. Drug release rate was investigated using USP IV flow-through cell and surface dissolution imaging system. Thinner films followed Fickian diffusion, and thicker films followed non-Fickian anomalous diffusion. Overall, the application of middle layer thickness could be used as a tool to manipulate drug load without the need for altering its formulation or precursor preparation by changing its thickness, hence achieving relatively high drug loading yet having sustained release of drug.
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7.
Clinical tolerance of corticospinal tracts in convection-enhanced delivery to the brainstem.
Morgenstern, PF, Zhou, Z, Wembacher-Schröder, E, Cina, V, Tsiouris, AJ, Souweidane, MM
Journal of neurosurgery. 2018;(6):1812-1818
Abstract
OBJECTIVE Convection-enhanced delivery (CED) has been explored as a therapeutic strategy for diffuse intrinsic pontine glioma (DIPG). Variables that may affect tolerance include infusate volume, infusion rate, catheter trajectory, and target position. Supratentorial approaches for catheter placement and infusate distribution patterns may conflict with corticospinal tracts (CSTs). The clinical relevance of these anatomical constraints has not been described. The authors report their experience using CED in the brainstem as it relates to anatomical CST conflict and association with clinical tolerance. METHODS In a phase I clinical trial of CED for DIPG (clinical trial registration no. NCT01502917, clinicaltrials.gov), a flexible infusion catheter was placed with MRI guidance for infusion of 124I-8H9, a radioimmunotherapeutic agent. Intra- and postprocedural MR images were analyzed to identify catheter trajectories and changes in T2-weighted signal intensity to approximate volume of distribution (Vd). Intersection of CST by the catheter and overlap between Vd and CST were recorded and their correlation with motor deficits was evaluated. RESULTS Thirty-one patients with a mean age of 7.6 years (range 3.2-18 years) underwent 39 catheter insertions for CED between 2012 and 2017. Thirty catheter insertions had tractography data available for analysis. The mean trajectory length was 105.5 mm (range 92.7-121.6 mm). The mean number of intersections of CST by catheter was 2.2 (range 0-3) and the mean intersecting length was 18.9 mm (range 0-44.2 mm). The first 9 infusions in the highest dose level (range 3.84-4.54 ml infusate) were analyzed for Vd overlap with CST. In this group, the mean age was 7.6 years (range 5.8-10.3 years), the mean trajectory length was 109.5 mm (range 102.6-122.3 mm), and the mean overlap between Vd and CST was 5.5 cm3. For catheter placement-related adverse events, 1 patient (3%) had worsening of a contralateral facial nerve palsy following the procedure with two CST intersections, an intersecting distance of 31.7 mm, and an overlap between Vd and CST of 3.64 cm3. For infusion-related adverse events, transient postinfusion deficits were noted in 3 patients in the highest dose level, with a mean number of 2 intersections of CST by catheter, mean intersecting length of 12.9 mm, and mean overlap between Vd and CST of 6.3 cm3. CONCLUSIONS A supratentorial approach to the brainstem crossing the CST resulted in one worsened neurological deficit. There does not appear to be a significant risk requiring avoidance of dominant motor fiber tracts with catheter trajectory planning. There was no correlation between Vd-CST overlap and neurological adverse events in this cohort.Clinical trial registration no.: NCT01502917 (clinicaltrials.gov).
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8.
Recent developments in solid lipid nanoparticle and surface-modified solid lipid nanoparticle delivery systems for oral delivery of phyto-bioactive compounds in various chronic diseases.
Ganesan, P, Ramalingam, P, Karthivashan, G, Ko, YT, Choi, DK
International journal of nanomedicine. 2018;:1569-1583
Abstract
Solid lipid nanoparticle (SLN) delivery systems have a wide applicability in the delivery of phyto-bioactive compounds to treat various chronic diseases, including diabetes, cancer, obesity and neurodegenerative diseases. The multiple benefits of SLN delivery include improved stability, smaller particle size, leaching prevention and enhanced lymphatic uptake of the bioactive compounds through oral delivery. However, the burst release makes the SLN delivery systems inadequate for the oral delivery of various phyto-bioactive compounds that can treat such chronic diseases. Recently, the surface-modified SLN (SMSLN) was observed to overcome this limitation for oral delivery of phyto-bioactive compounds, and there is growing evidence of an enhanced uptake of curcumin delivered orally via SMSLNs in the brain. This review focuses on different SLN and SMSLN systems that are useful for oral delivery of phyto-bioactive compounds to treat various chronic diseases.
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9.
Local Antibiotic Delivery Systems: Current and Future Applications for Diabetic Foot Infections.
Markakis, K, Faris, AR, Sharaf, H, Faris, B, Rees, S, Bowling, FL
The international journal of lower extremity wounds. 2018;(1):14-21
Abstract
Foot infections are common among diabetic patients with peripheral neuropathy and/or peripheral arterial disease, and it can be the pivotal event leading to a minor or major amputation of the lower extremity. Treatment of diabetic foot infections, especially deep-seated ones, remains challenging, in part because impaired blood perfusion and the presence of biofilms can impair the effectiveness of systemic antibiotics. The local application of antibiotics is an emerging field in the treatment of diabetic foot infections, with demonstrable advantages. These include delivery of high concentrations of antibiotics in the affected area, limited systemic absorption, and thus negligible side effects. Biodegradable vehicles, such as calcium sulfate beads, are the prototypical system, providing a good elution profile and the ability to be impregnated with a variety of antibiotics. These have largely superseded the nonbiodegradable vehicles, but the strongest evidence available is for calcium bead implantation for osteomyelitis management. Natural polymers, such as collagen sponge, are an emerging class of delivery systems, although thus far, data on diabetic foot infections are limited. There is recent interest in the novel antimicrobial peptide pexiganan in the form of cream, which is active against most of the microorganisms isolated in diabetic foot infections. These are promising developments, but randomized trials are required to ascertain the efficacy of these systems and to define the indications for their use. Currently, the role of topical antibiotic agents in treating diabetic foot infections is limited and outside of routine practice.
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10.
Plant-Mediated Synthesis and Applications of Iron Nanoparticles.
Ebrahiminezhad, A, Zare-Hoseinabadi, A, Sarmah, AK, Taghizadeh, S, Ghasemi, Y, Berenjian, A
Molecular biotechnology. 2018;(2):154-168
Abstract
Nanoscale iron particles have attracted substantial interest due to their unique physical and chemical properties. Over the years, various physical and chemical methods have been developed to synthesize these nanostructures which are usually expensive and potentially harmful to human health and the environment. Synthesis of iron nanoparticles (INPs) by using plant extract is now of great interest in order to develop a novel and sustainable approach toward green chemistry. In this method the chemical compounds and organic solvents are replaced with phytochemicals and aqueous matrixes, respectively. Similar to any chemical and biochemical reaction, factors such as reaction temperature, concentration of iron precursor, concentration of leaf extract, and reaction time have critical effects on the reaction yield. This review focuses on the novel approaches used for green synthesis of INPs by using plant resources. The currently available statistics including the factors affecting the synthesis process and potential applications of the fabricated nanoparticles are discussed. Recommendations are also given for areas of future research in order to improve the production process.