Application of pectin in oral drug delivery

β-Cyclodextrin mediated controlled release of phenothiazine from pH-responsive pectin and pullulan-based hydrogel optimized through experimental design

Drugs with lower permeability and water solubility provide major challenges for producing safe and efficient formulations. The current work aims to prepare ICs of the drug phenothiazine and β-cyclodextrin via physical, microwave, freeze-drying, and kneading methods. Many analytical methods, such as 1H NMR, ROESY, FT-IR, DSC, SEM, and XRD, were then used to confirm the formation of inclusion complexes. The natural polysaccharide-based hydrogel comprising pectin and pullulan was synthesized in air and optimized through various parameters. In order to maximize the reaction parameters, Response Surface Methodology design was employed for experimental optimization. We use FT-IR, TGA, SEM, EDX, and XRD to investigate hydrogel formation. At 37 °C, an investigation was carried out on the in vitro controlled release of PN at pH 2, 7, and 7.4. The analysis of drug release data revealed that PM and KM exhibited an initial burst release of drugs, with the MW and FD method proving to be the most suitable approach for achieving precise ICs of PN and β-CD for sustained drug release. The kinetics of drug release were evaluated using various kinetic models, with the Riteger-Peppas and Peppas-Sahlin models demonstrating the best fit for drug release in all instances.

Advanced polymers and recent advancements on gastroretentive drug delivery system; a comprehensive review

Oral route of drug administration is typically the initial option for drug administration because it is both practical and affordable. However, major drawback of this route includes the release of drug at a specified place thus reduces the bioavailability. This could be overcome by utilising the gastroretentive drug delivery system (GRRDS). Prolonged stomach retention improves bioavailability and increases solubility for medicines that are unable to dissolve in high pH environments. Many recent advancements in the floating, bio adhesive, magnetic, expandable, raft forming and ion exchange systems have been made that had led towards advanced form of drug delivery. From the past few years, floating drug delivery system has been most commonly utilised for the delivery of drug in a delayed manner. Various polymers have been utilised for manufacturing of these systems, including alginates, chitosan, pectin, carrageenan's, xanthan gum, hydroxypropyl cellulose, carbomer, polyethylene oxide and sodium carboxy methyl cellulose. Chitosan, pectin and xanthan gum have been found to be most commonly used polymers in the manufacturing of drug inclusion complex for gastroretentive drug delivery. This study aimed to define various types and advanced polymers as well as also highlights recent advances and future perspectives of gastroretentive drug delivery system.

Tissue regeneration properties of hydrogels derived from biological macromolecules: A review

The successful tissue engineering depends on the development of biologically active scaffolds that possess optimal characteristics to effectively support cellular functions, maintain structural integrity and aid in tissue regeneration. Hydrogels have emerged as promising candidates in tissue regeneration due to their resemblance to the natural extracellular matrix and their ability to support cell survival and proliferation. The integration of hydrogel scaffold into the polymer has a variable impact on the pseudo extracellular environment, fostering cell growth/repair. The modification in size, shape, surface morphology and porosity of hydrogel scaffolds has consequently paved the way for addressing diverse challenges in the tissue engineering process such as tissue architecture, vascularization and simultaneous seeding of multiple cells. The present review provides a comprehensive update on hydrogel production using natural and synthetic biomaterials and their underlying mechanisms. Furthermore, it delves into the application of hydrogel scaffolds in tissue engineering for cardiac tissues, cartilage tissue, adipose tissue, nerve tissue and bone tissue. Besides, the present article also highlights various clinical studies, patents, and the limitations associated with hydrogel-based scaffolds in recent times.

Colon Drug Delivery Systems Based on Swellable and Microbially Degradable High-Methoxyl Pectin: Coating Process and In Vitro Performance

Oral colon delivery systems based on a dual targeting strategy, harnessing time- and microbiota-dependent release mechanisms, were designed in the form of a drug-containing core, a swellable/biodegradable polysaccharide inner layer and a gastroresistant outer film. High-methoxyl pectin was employed as the functional coating polymer and was applied by spray-coating or powder-layering. Stratification of pectin powder required the use of low-viscosity hydroxypropyl methylcellulose in water solution as the binder. These coatings exhibited rough surfaces and higher thicknesses than the spray-coated ones. Using a finer powder fraction improved the process outcome, coating quality and inherent barrier properties in aqueous fluids. Pulsatile release profiles and reproducible lag phases of the pursued duration were obtained from systems manufactured by both techniques. This performance was confirmed by double-coated systems, provided with a Kollicoat® MAE outer film that yielded resistance in the acidic stage of the test. Moreover, HM pectin-based coatings manufactured by powder-layering, tested in the presence of bacteria from a Crohn's disease patient, showed earlier release, supporting the role of microbial degradation as a triggering mechanism at the target site. The overall results highlighted viable coating options and in vitro release characteristics, sparking new interest in naturally occurring pectin as a coating agent for oral colon delivery.

Pectin hydrogels for controlled drug release: Recent developments and future prospects

Pectin hydrogels have emerged as a highly promising medium for the controlled release of pharmaceuticals in the dynamic field of drug delivery. The present review sheds light on the broad range of applications and potential of pectin-based hydrogels in pharmaceutical formulations. Pectin, as a biopolymer, is a versatile candidate for various drug delivery systems because of its wide range of properties and characteristics. The information provided on formulation strategies and crosslinking techniques provides researchers with tools to improve drug entrapment and controlled release. Furthermore, this review provides a more in-depth understanding of the complex factors influencing drug release from pectin hydrogels, such as the impact of environmental conditions and drug-specific characteristics. Pectin hydrogels demonstrate adaptability across diverse domains, ranging from applications in oral and transdermal drug delivery to contributions in wound healing, tissue engineering, and ongoing clinical trials. While standardization and regulatory compliance remain significant challenges, the future of pectin hydrogels appears to be bright, opening up new possibilities for advanced drug delivery systems.

3D printed polylactic acid-based nanocomposite scaffold stuffed with microporous simvastatin-loaded polyelectrolyte for craniofacial reconstruction

Critical sized craniofacial defects are among the most challenging bone defects to repair, due to the anatomical complexity and aesthetic importance. In this study, a polylactic acid/hardystonite-graphene oxide (PLA/HTGO) scaffold was fabricated through 3D printing. In order to upgrade the 3D printed scaffold to a highly porous scaffold, its channels were filled with pectin-quaternized chitosan (Pec-QCs) polyelectrolyte solution containing 0 or 20 mg/mL of simvastatin (Sim) and then freeze-dried. These scaffolds were named FD and FD-Sim, respectively. Also, similar PLA/HTGO scaffolds were prepared and dip coated with Pec-QCs solution containing 0 or 20 mg/mL of Sim and were named DC and DC-Sim, respectively. The formation of macro/microporous structure was confirmed by morphological investigations. The release of Sim from DC-Sim and FD-Sim scaffolds after 28 days was measured as 77.40 ± 5.25 and 86.02 ± 3.63 %, respectively. Cytocompatibility assessments showed that MG-63 cells had the highest proliferation, attachment and spread on the Sim containing scaffolds, especially FD-Sim. In vivo studies on a rat calvarial defect model revealed that an almost complete recovery occurred in the group treated with FD-Sim scaffold after 8 weeks and the defect was filled with newly formed bone. The results of this study acknowledge that the FD-Sim scaffold can be a perfect candidate for calvarial defect repair.

Characteristics of Interpolyelectrolyte Complexes Based on Different Types of Pectin with Eudragit® EPO as Novel Carriers for Colon-Specific Drug Delivery

Given that pectin is a well-known substance used for drug delivery, we aimed to obtain and further examine the efficacy of interpolyelectrolyte complexes based on citrus or apple pectin and the Eudragit® EPO for using these carriers in oral drug delivery. To characterize the physicochemical properties of these compounds, turbidity, gravimetry, viscosity, elementary analysis, FTIR spectroscopy, and DSC analysis were utilized. Diffusion transport characteristics were evaluated to assess the swelling ability of the matrices and the release of diclofenac sodium. To examine the release parameters, mathematical modeling was performed by using the Korsmayer-Peppas and Logistic equations as well. During the turbidity study, stoichiometry compositions were selected for the developed IPECs EPO/PecA and EPO/PecC at pH values = 4.0, 5.0, 6.0, and 7.0. The FTIR spectra of the complexes were characterized by an increase in the intensity of the bands at 1610 cm-1 and 1400 cm-1. According to the DSC analysis, IPEC has a certain Tg = 57.3 °C. The highest release rates were obtained for IPEC EPO/PecC_1 and EPO/PecC_4. The mechanism of drug transport from the matrices IPEC EPO/PecC, IPEC EPO/PecA_3, and EPO/PecA_4 can be characterized as Super Case II. Anomalous release (non-Fickian release) is typical for IPEC EPO/PecA_1 and EPO/PecA_2. Thus, the resulting systems can be further used for the effective delivery of the drugs to the colon.

Plant-derived polyphenolic compounds: nanodelivery through polysaccharide-based systems to improve the biological properties

Plant-derived polyphenols are naturally occurring compounds widely distributed in plants. They have received greater attention in the food and pharmaceutical industries due to their potential health benefits, reducing the risk of some chronic diseases due to their antioxidant, anti-inflammatory, anticancer, cardioprotective, and neuro-action properties. Polyphenolic compounds orally administered can be used as adjuvants in several treatments but with restricted uses due to chemical instability. The review discusses the different structural compositions of polyphenols and their influence on chemical stability. Despite the potential and wide applications, there is a need to improve the delivery of polyphenolics to target the human intestine without massive chemical modifications. Oral administration of polyphenols is unfeasible due to instability, low bioaccessibility, and limited bioavailability. Nano-delivery systems based on polysaccharides (starch, pectin, chitosan, and cellulose) have been identified as a viable option for oral ingestion, potentiate biological effects, and direct-controlled delivery in specific tissues. The time and dose can be individualized for specific diseases, such as intestinal cancer. This review will address the mechanisms by which polysaccharides-based nanostructured systems can protect against degradation and enhance intestinal permeation, oral bioavailability, and the potential application of polysaccharides as nanocarriers for the controlled and targeted delivery of polyphenolic compounds.

Preparation and Characterization of Hydrogel Films and Nanoparticles Based on Low-Esterified Pectin for Anticancer Applications

Prospective adjuvant anticancer therapy development includes the establishing of drug delivery systems based on biocompatible and biodegradable carriers. We have designed films and nanoparticles (NPs) based on low-esterified pectin hydrogel using the ionic gelation method. We investigated morphology, nanomechanical properties, biocompatibility and anticancer activity. Hydrogel films are characterized by tunable viscoelastic properties and surface nanoarchitectonics through pectin concentration and esterification degree (DE), expressed in variable pore frequency and diameter. An in vitro study showed a significant reduction in metabolic activity and the proliferation of the U87MG human glioblastoma cell line, probably affected via the adhesion mechanism. Glioma cells formed neurosphere-like conglomerates with a small number of neurites when cultured on fully de-esterified pectin films and they did not produce neurites on the films prepared on 50% esterified pectin. Pectin NPs were examined in terms of size distribution and nanomechanical properties. The NPs' shapes were proved spherical with a mean diameter varying in the range of 90-115 nm, and a negative zeta potential from -8.30 to -7.86 mV, which indicated their stability. The NPs did not demonstrate toxic effect on cells or metabolism inhibition, indicating good biocompatibility. Nanostructured biomaterials prepared on low-esterified pectins could be of interest for biomedical applications in adjuvant anticancer therapy and for designing drug delivery systems.

Interaction between ultrasound-modified pectin and icaritin

Pectin can improve the bioaccessibility of icaritin as a nanocarrier, and ultrasound can modify the pectin structure. However, the interaction between ultrasound-modified pectin (UMP) and icaritin remains unclearly. In this work, the effects of UMP on the physiochemical properties of icaritin/pectin micelles (IPMs) were investigated. The IPMs prepared with UMP (UMP-IPMs) showed lower encapsulation efficiencies and loading capacities, comparing with native IPMs. UMP-IPMs had smaller particle sizes (325-399 nm) than native IPMs (551 nm). The Mw, viscosity, G' and G" of pectin were determined. NMR spectra indicated that the repeating unit in pectins remained consistently before and after ultrasound treatment, and 7-OH of icaritin was involved in hydrogen bond formation with pectin. The larger chemical shift movement of 6-H and 7-OH for U3-IPMs than P0-IPMs suggested that stronger hydrogen bond interaction between icaritin and pectin. UMP-IPMs exhibited stronger anti-proliferation activities against HepG2 cells than native IPMs.

Recent advances in cellulose, pectin, carrageenan and alginate-based oral drug delivery systems

Polymers-based drug delivery systems constitute one of the highly explored thrust areas in the field of the medicinal and pharmaceutical industries. In the past years, the properties of polymers have been modified in context to their solubility, release kinetics, targeted action site, absorption, and therapeutic efficacy. Despite the availability of diverse synthetic polymers for the bioavailability enhancement of drugs, the use of natural polymers is still highly recommended due to their easy availability, accessibility, and non-toxicity. The aim of the review is to provide the available literature of the last five years on oral drug delivery systems based on four natural polymers i.e., cellulose, pectin, carrageenan, and alginate in a concise and tabulated manner. In this review, most of the information is in tabulated form to provide easy accessibility to the reader. The data related to active pharmaceutical ingredients and supported components in different formulations of the mentioned polymers have been made available.

Valorization of polyphenolic compounds from food industry by-products for application in polysaccharide-based nanoparticles

In the last decades, evidence has indicated the beneficial properties of dietary polyphenols. In vitro and in vivo studies support that the regular intake of these compounds may be a strategy to reduce the risks of some chronic non-communicable diseases. Despite their beneficial properties, they are poorly bioavailable compounds. Thus, the main objective of this review is to explore how nanotechnology improves human health while reducing environmental impacts with the sustainable use of vegetable residues, from extraction to the development of functional foods and supplements. This extensive literature review discusses different studies based on the application of nanotechnology to stabilize polyphenolic compounds and maintain their physical-chemical stability. Food industries commonly generate a significant amount of solid waste. Exploring the bioactive compounds of solid waste has been considered a sustainable strategy in line with emerging global sustainability needs. Nanotechnology can be an efficient tool to overcome the challenge of molecular instability, especially using polysaccharides such as pectin as assembling material. Complex polysaccharides are biomaterials that can be extracted from citrus and apple peels (from the juice industries) and constitute promising wall material stabilizing chemically sensitive compounds. Pectin is an excellent biomaterial to form nanostructures, as it has low toxicity, is biocompatible, and is resistant to human enzymes. The potential extraction of polyphenols and polysaccharides from residues and their inclusion in food supplements may be a possible application to reduce environmental impacts and constitutes an approach for effectively including bioactive compounds in the human diet. Extracting polyphenolics from industrial waste and using nanotechnology may be feasible to add value to food by-products, reduce impacts on nature and preserve the properties of these compounds.

Hexavalent chromium detoxification by haloalkaliphilic Nesterenkonia sp strain NRC-Y immobilized in different matrices.. [DOI: 10.21203/rs.3.rs-2870155/v1] [Citation(s) in RCA: 0] [Impact Index Per Article: 0]

In order to develop a bioprocess for Cr(VI) detoxification in industrial effluent, a previously isolated potent Cr(VI) reducing haloalkaliphilic Nesterenkonia sp strain NRC-Y was immobilized in nine different matrices including natural polymer, modified natural, synthetic and mixtures of natural and synthetic polymers and investigated for Cr(VI) detoxification. Among the tested carriers and immobilization approaches, Nesterenkonia sp NRC-Y cells encapsulated in amidated pectin beads showed highest Cr(VI) reduction efficiency (58.4% of initial Cr(VI) concentration 150 mg/L after 20 h), followed by alginate, alginate-PVA, alginate-PVA-chitosan, PVA-PVP, and PVA respectively. Therefore, amidated pectin was selected for further investigation and immobilization of both whole cells and chromate reductase. Operational stability study revealed that immobilized whole cell was more efficient and stable than immobilized chromate reductase and the free cells retaining about 60%, 27.0% and 11.5% of its initial activity after four successive batches, respectively. The temperature and pH optima for the immobilized cells were 35⸰C and 7.0, respectively. The pH and thermal stability of Nesterenkonia sp NRC-Y cells were significantly enhanced upon immobilization in amidated pectin beads. The developed immobilized biocatalyst was applied for Cr(VI) reduction in industrial effluent samples, and was able to completely reduce Cr(VI) within 4 and 8 h for effluents for initial Cr(VI) concentrations of 10 and 30 mg/L, respectively. To the best of our knowledge, this is the first report about of Cr(VI) detoxification by immobilized Nesterenkonia sp NRC-Y in amidated pectin beads. The developed immobilized biocatalyst is promising and has the potential for large-scale Cr(VI) detoxification application.

Development of iron-vitamin multilayer encapsulates using 3 fluid nozzle spray drying

Considering the growing concern of iron and folic acid deficiency, encapsulation of these nutrients and fortification into foods is emerging as an effective counter-strategy. The present work focuses on a scalable approach for the production of iron, ascorbic acid, and folic acid core-shell encapsulates using novel 3-fluid nozzle (3FN) spray drying with whey protein as core and either pectin or hydroxypropyl methylcellulose (HPMC) as shell polymers. The effect of shell formation was observed by comparing core-shell encapsulates with conventional 2-fluid nozzle (2FN) encapsulates. Also, the effect of pH of whey protein on the color of encapsulates is noteworthy; reducing the pH to 4.0 significantly improved the lightness value (52.91 ± 0.13) when compared with the encapsulates with native pH (38.91 ± 0.58). Furthermore, sample with pectin as shell polymer exhibited fair flowability with lowest values of Hausner ratio (1.25 ± 0.04) and Carr's index (20.06 ± 2.71) and highest encapsulation efficiency for folic acid (86.07 ± 5.24%). Whereas, encapsulates having HPMC as shell polymer showed highest lightness value (60.80 ± 0.32) and highest encapsulation efficiency for iron (87.28 ± 4.15%). The formation of core-shell structure was confirmed by evaluation of the surface composition which showed reduced amine bonds and increased aliphatic and carbonyl bonds in the encapsulates prepared by 3FN spray drying. The encapsulates prepared without adjusting whey protein pH showed the least release (∼51 % in 24 h) and bioaccessibility (∼56%) of iron indicating the iron-whey protein complex formation. Based on appearance, smooth surface morphology, flowability, and release behavior, a combination of whey protein and pectin is recommended for co-encapsulation of iron, folic acid and ascorbic acid.

Ca2+-Responsive Glyco-insulin

Chemical modification of peptides and proteins, such as PEGylation and lipidation, creates conjugates with new properties. However, they are typically not dynamic or stimuli-responsive. Self-assembly controlled by a stimulus will allow adjusting properties directly. Here, we report that conjugates of oligogalacturonic acids (OGAs), isolated from plant-derived pectin, are Ca²⁺-responsive. We report the conjugation of OGA to human insulin (HI) to create new glyco-insulins. In addition, we coupled OGA to model peptides. We studied their self-assembly by dynamic light scattering, small-angle X-ray scattering, and circular dichroism, which showed that the self-assembly to form nanostructures depended on the length of the OGA sequence and Zn²⁺ and Ca²⁺ concentrations. Subcutaneous administration of OGA12-HI with Zn²⁺ showed a stable decrease in blood glucose over a longer period of time compared to HI, despite the lower receptor binding affinity.

Multifunctional hydrogels based on chitosan, hyaluronic acid and other biological macromolecules for the treatment of inflammatory bowel disease: A review

Hydrogel is a three-dimensional network polymer material rich in water. It is widely used in the biomedical field because of its unique physical and chemical properties and good biocompatibility. In recent years, the incidence of inflammatory bowel disease (IBD) has gradually increased, and the disadvantages caused by traditional drug treatment of IBD have emerged. Therefore, there is an urgent need for new treatments to alleviate IBD. Hydrogel has become a potential therapeutic platform. However, there is a lack of comprehensive review of functional hydrogels for IBD treatment. This paper first summarizes the pathological changes in IBD sites. Then, the action mechanisms of hydrogels prepared from chitosan, sodium alginate, hyaluronic acid, functionalized polyethylene glycol, cellulose, pectin, and γ-polyglutamic acid on IBD were described from aspects of drug delivery, peptide and protein delivery, biologic therapies, loading probiotics, etc. In addition, the advanced functions of IBD treatment hydrogels were summarized, with emphasis on adhesion, synergistic therapy, pH sensitivity, particle size, and temperature sensitivity. Finally, the future development direction of IBD treatment hydrogels has been prospected.

In vitro and in vivo evaluation of a pH-, microbiota- and time-based oral delivery platform for colonic release

Several formulation strategies have been proposed for oral colon delivery, particularly for the therapy of inflammatory bowel disease (IBD). However, targeting the large intestine remains a challenging goal. The aim of this study was to develop and evaluate a novel type of drug delivery system, which is based on multiple drug release triggers for reliable performance. The system consists of: (i) a drug core, (ii) an inner swellable low-viscosity hydroxypropyl methylcellulose (HPMC) layer, and (iii) an outer film coating based on a Eudragit® S:high-methoxyl (HM) pectin (7:3 w/w) blend, optionally containing chitosan. Convex immediate release tablets (2 or 4 mm in diameter) containing paracetamol or 5-aminosalicylic acid (5-ASA) were coated in a fluid bed. The double-coated tablets exhibited pulsatile release profiles when changing the release medium from 0.1 N HCl to phosphate buffer pH 7.4. Also, drug release was faster in simulated colonic fluid (SCF) in the presence of fecal bacteria from IBD patients compared to control culture medium from tablets with outer Eudragit® S: HM pectin: chitosan coatings. The latter systems showed promising results in the control of the progression of colitis and alteration of the microbiota in a preliminary rat study.

Preparation and in vitro evaluation of hot-melt extruded pectin-based pellets containing ketoprofen for colon targeting

This work developed high drug-load pellets for colon targeting in minimal steps by coupling hot-melt extrusion (HME) with a die-surface cutting pelletizer, offering a potential continuous pellet manufacturing process. Ketoprofen (KTP) was selected as a model drug for this study due to its thermal stability and severe upper gastrointestinal side effects. Low and high methoxyl grade pectins were the enzyme-triggered release matrix, and hydroxypropyl methylcellulose (HME 4 M/HME 100LV) was used as a premature release-retarding agent. The powder X-ray diffraction technique and the differential scanning calorimetry results revealed that KTP exists in the solid-solution state within the polymeric matrix after the HME step. The scanning electron micrographs of the fabricated pellets showed a smooth surface without any cracks. The lead formulation showed the lowest premature drug release (∼13%) with an extended KTP release profile over a 24 h period in the presence and absence of the release-triggering enzyme. The lead formulation was stable for 3 months at accelerated stability conditions (40 °C/75 ± 5% RH) concerning drug content, in vitro release, and thermal characteristics. In summary, coupling HME and pelletization processes could be a promising technology for developing colon-targeted drug delivery systems.

Mucoadhesive carriers for oral drug delivery

Among the various dosage forms, oral medicine has extensive benefits including ease of administration and patients' compliance, over injectable, suppositories, ocular and nasal. Despite of extensive demand and emerging advantages, over 50% of therapeutic molecules are not available in oral form due to their physicochemical properties. More importantly, most of the biologics, proteins, peptide, and large molecular drugs are mostly available in injectable form. Conventional oral drug delivery system has limitation such as degradation and lack of stability within stomach due to presence of highly acidic gastric fluid, hinders their therapeutic efficacy and demand more frequent and higher dosing. Hence, formulation for controlled, sustained, and targeted drug delivery, need to be designed with feasibility to target the specific region of gastrointestinal (GI) tract such as stomach, small intestine, intestine lymphatic, and colon is challenging. Among various oral delivery approaches, mucoadhesive vehicles are promising and has potential for improving oral drug retention and controlled absorption to treat local diseases within the GI tract, as well systemic diseases. This review provides the overview about the challenges and opportunities to design mucoadhesive formulation for oral delivery of therapeutics in a way to target the specific region of the GI tract. Finally, we have concluded with future perspective and potential of mucoadhesive formulations for oral local and systemic delivery.

Various Coated Barrier Membranes for Better Guided Bone Regeneration: A Review

A good barrier membrane is one of the important factors for effective guided bone/tissue regeneration (GBR/GTR) in the case of periodontal bone defects. Several methods are being discussed to overcome and improve the shortcomings of commercially available membranes. One of the methods is to coat the membrane with bioactive materials. In this study, 41 studies related to coated membranes for GBR/GTR published in the last 5 years were reviewed. These studies reported coating the membrane with various bioactive materials through different techniques to improve osteogenesis, antimicrobial properties, and physical/mechanical properties. The reported studies have been classified and discussed based on the purpose of coating. The goal of the most actively studied research on coating or surface modification of membranes is to improve new bone formation. For this purpose, calcium phosphate, bioactive glass, polydopamine, osteoinduced drugs, chitosan, platelet-rich fibrin, enamel matrix derivatives, amelotin, hyaluronic acid, tantalum, and copper were used as membrane coating materials. The paradigm of barrier membranes is changing from only inert (or biocompatible) physical barriers to bioactive osteo-immunomodulatory for effective guided bone and tissue regeneration. However, there is a limitation that there exists only a few clinical studies on humans to date. Efforts are needed to implement the use of coated membranes from the laboratory bench to the dental chair unit. Further clinical studies are needed in the patients’ group for long-term follow-up to confirm the effect of various coating materials.

Synthesis and characterization of photo-crosslinkable cinnamate-functionalized pectin

The polysaccharide pectin (PC) was functionalized with the photo-responsive cinnamic acid hydrazide (CN) to produce the photo-crosslinkable PC-CN hydrogel material that was then evaluated as a carrier for encapsulation of the drug model aspirin. Cinnamic acid hydrazide was first prepared and then incorporated with the abundant -COOCH₃ groups on the pectin chain via hydrazide linkage. The obtained polymeric derivatives have been characterized by means of instrumental techniques including FTIR and NMR. The obtained PC-CN hydrogels with different cinnamic functionality were also freeze-dried and examined by SEM, which indicated more coherent hydrogel texture by increasing the cinnamic functionalization. The effect of the photo-curing time, as well as the functionalization degree, on the swelling and gelation of the obtained hydrogel was also studied to evaluate the potential of the developed material in drug delivery systems using aspirin as a common and available drug model. The developed PC-CN hydrogel materials exhibited high potential as a drug carrier that enables the control of the drug release via optimizing both the degree of cinnamic functionality and the photo-curing time.

Dual crosslinking of folic acid-modified pectin nanoparticles for enhanced oral insulin delivery

Pectin-based drug delivery systems hold great potential for oral insulin delivery, since they possess excellent gelling property, good mucoadhesion and high stability in the gastrointestinal (GI) tract. However, lack of enterocyte targeting ability and premature drug release in the upper GI tract of the susceptible ionic-crosslinked pectin matrices are two major problems to be solved. To address these issues, we developed folic acid (FA)-modified pectin nanoparticles (INS/DFAN) as insulin delivery vehicles by a dual-crosslinking method using calcium ions and adipic dihydrazide (ADH) as crosslinkers. In vitro studies indicated insulin release behaviors of INS/DFAN depended on COOH/ADH molar ratio in the dual-crosslinking process. INS/DFAN effectively prevented premature insulin release in simulated GI fluids compared to ionic-crosslinked nanoparticles (INS/FAN). At an optimized COOH/ADH molar ratio, INS/DFAN with FA graft ratio of 18.2% exhibited a relatively small particle size, high encapsulation efficiency and excellent stability. Cellular uptake of INS/DFAN was FA graft ratio dependent when it was at/below 18.2%. Uptake mechanism and intestinal distribution studies demonstrated the enhanced insulin transepithelial transport by INS/DFAN via FA carrier-mediated transport pathway. In vivo studies revealed that orally-administered INS/DFAN produced a significant reduction in blood glucose levels and further improved insulin bioavailability in type I diabetic rats compared to INS/FAN. Taken together, the combination of dual crosslinking and FA modification is an effective strategy to develop pectin nano-vehicles for enhanced oral insulin delivery.

Optical and Mechanical Properties of Self-Repairing Pectin Biopolymers

Pectin’s unique physicochemical properties have been linked to a variety of reparative and regenerative processes in nature. To investigate the effect of water on pectin repair, we used a 5 mm stainless-steel uniaxial load to fracture glass phase pectin films. The fractured gel phase films were placed on a 1.5–1.8 mm thick layer of water and incubated for 8 h at room temperature and ambient humidity. There was no immersion or agitation. The repaired pectin film was subsequently assessed for its optical and mechanical properties. Light microscopy demonstrated repair of the detectable fracture area and restoration of the films’ optical properties. The burst strength of the repaired film declined to 55% of the original film. However, its resilience was restored to 87% of the original film. Finally, a comparison of the initial and post-repair fracture patterns demonstrated no recurrent fissures in the repaired glass phase films. The water-induced repair of the pectin film was superior to the optical and mechanical properties of the repaired films composed of nanocellulose fibers, sodium hyaluronate, and oxidized cellulose. We conclude that the unique physicochemical properties of pectin facilitate the water-induced self-repair of fractured pectin films.

Evaluation of Extended-Release of Piroxicam Loaded Pectin-Zein Hydrogel Microspheres: In Vitro, Ex Vivo, and In Vivo Studies

OBJECTIVE

This study evaluated drug delivery systems based on Pectin (P) and Zein (Z) hydrogel microspheres. Piroxicam (Px) loaded P/Z hydrogel microspheres (P/Z HM) were developed, and their extended-release pharmacokinetic properties were evaluated.

METHODS

Experiments were executed under three different conditions: in vitro, ex vivo, and in vivo. Then, the in vitro-in vivo correlations (IVIVC) and ex vivo - in vivo correlations (EVIVC) were examined.

RESULTS

Analysis of drug release mechanisms were evaluated by fitting the in vitro data into the Ritger-Peppas equation, showing the contribution of both polymers' relaxation and drug diffusion from the hydrogel microspheres. The fraction absorbed in vivo was determined by the deconvolution of plasma concentration data using the Loo-Riegelman method. After oral single-dose administration of the two formulations, their basic independent model parameters were calculated.

CONCLUSION

P/Z HM had different drug release behaviors in in vitro and in vivo conditions. However, the ex vivo and in vivo characteristics were similar (R² = 0.99). This seemed reasonable to use the ex vivo method to predict the in vivo drug absorption behavior during the polymeric drug delivery system developmental studies. The P/Z HM formulation maintained the drug dose at the colon site for a long duration and could be applied for delivery of active pharmaceutical and food ingredients to the colon site.

Polysaccharide-Drug Conjugates: A Tool for Enhanced Cancer Therapy

Cancer is one of the most widespread deadly diseases, following cardiovascular disease, worldwide. Chemotherapy is widely used in combination with surgery, hormone and radiation therapy to treat various cancers. However, chemotherapeutic drugs can cause severe side effects due to non-specific targeting, poor bioavailability, low therapeutic indices, and high dose requirements. Several drug carriers successfully overcome these issues and deliver drugs to the desired sites, reducing the side effects. Among various drug delivery systems, polysaccharide-based carriers that target only the cancer cells have been developed to overcome the toxicity of chemotherapeutics. Polysaccharides are non-toxic, biodegradable, hydrophilic biopolymers that can be easily modified chemically to improve the bioavailability and stability for delivering therapeutics into cancer tissues. Different polysaccharides, such as chitosan, alginates, cyclodextrin, pullulan, hyaluronic acid, dextran, guar gum, pectin, and cellulose, have been used in anti-cancer drug delivery systems. This review highlights the recent progress made in polysaccharides-based drug carriers in anti-cancer therapy.

Clinical translation of advanced colonic drug delivery technologies

Targeted drug delivery to the colon offers a myriad of benefits, including treatment of local diseases, direct access to unique therapeutic targets and the potential for increasing systemic drug bioavailability and efficacy. Although a range of traditional colonic delivery technologies are available, these systems exhibit inconsistent drug release due to physiological variability between and within individuals, which may be further exacerbated by underlying disease states. In recent years, significant translational and commercial advances have been made with the introduction of new technologies that incorporate independent multi-stimuli release mechanisms (pH and/or microbiota-dependent release). Harnessing these advanced technologies offers new possibilities for drug delivery via the colon, including the delivery of biopharmaceuticals, vaccines, nutrients, and microbiome therapeutics for the treatment of both local and systemic diseases. This review details the latest advances in colonic drug delivery, with an emphasis on emerging therapeutic opportunities and clinical technology translation.

Optimization of calcium pectinate gel production from high methoxyl pectin

BACKGROUND

Calcium pectinate (CaP) gel is traditionally prepared by de-esterifying high methoxyl pectin (HMP) to low methoxyl pectin (LMP), followed by gelation with calcium. To save both time and cost in the production of CaP gel, an alternative method was developed by the addition of CaCl₂ to HMP at alkaline pH. To optimize the production, response surface methodology (RSM) was used to investigate the effects of temperature (30-50 °C), time (20-40 min) and pH (8-10) on yield, calcium content of the CaP gel and the degree of esterification (DE) of pectin following decalcification of CaP (DC-pectin).

RESULTS

The linear term for pH had a significant effect (P < 0.01) on all three responses, whereas interaction effects were not significant (P > 0.01), except on the calcium content (P < 0.01). The optimized process conditions (temperature, time and pH) to obtain maximum CaP-HMP gel yield (88.83%) were 50 °C, 40 min and pH 9.6, and for the highest calcium content (97.23 mg g^-1 ) they were 40 °C, 30 min and pH 9.7. DC-pectin was a typical LMP with DE varying from 26.92% to 50.33%. The DE of DC-pectin could be predicted by a model that proved significant (R²  = 0.9888).

CONCLUSION

The optimum conditions were established to produce CaP gels from HMP with high yield and calcium content. Also, LMP with predictable DE can be produced following a significant model. This study provides new insights into the production and application of CaP gel. © 2021 Society of Chemical Industry.

Current Advances in Lipid and Polymeric Antimicrobial Peptide Delivery Systems and Coatings for the Prevention and Treatment of Bacterial Infections

Bacterial infections constitute a threat to public health as antibiotics are becoming less effective due to the emergence of antimicrobial resistant strains and biofilm and persister formation. Antimicrobial peptides (AMPs) are considered excellent alternatives to antibiotics; however, they suffer from limitations related to their peptidic nature and possible toxicity. The present review critically evaluates the chemical characteristics and antibacterial effects of lipid and polymeric AMP delivery systems and coatings that offer the promise of enhancing the efficacy of AMPs, reducing their limitations and prolonging their half-life. Unfortunately, the antibacterial activities of these systems and coatings have mainly been evaluated in vitro against planktonic bacteria in less biologically relevant conditions, with only some studies focusing on the antibiofilm activities of the formulated AMPs and on the antibacterial effects in animal models. Further improvements of lipid and polymeric AMP delivery systems and coatings may involve the functionalization of these systems to better target the infections and an analysis of the antibacterial activities in biologically relevant environments. Based on the available data we proposed which polymeric AMP delivery system or coatings could be profitable for the treatment of the different hard-to-treat infections, such as bloodstream infections and catheter- or implant-related infections.

Natural Products with Activity against Lung Cancer: A Review Focusing on the Tumor Microenvironment

Lung cancer is one of the most prevalent malignancies worldwide. Despite the undeniable progress in lung cancer research made over the past decade, it is still the leading cause of cancer-related deaths and continues to challenge scientists and researchers engaged in searching for therapeutics and drugs. The tumor microenvironment (TME) is recognized as one of the major hallmarks of epithelial cancers, including the majority of lung cancers, and is associated with tumorigenesis, progression, invasion, and metastasis. Targeting of the TME has received increasing attention in recent years. Natural products have historically made substantial contributions to pharmacotherapy, especially for cancer. In this review, we emphasize the role of the TME and summarize the experimental proof demonstrating the antitumor effects and underlying mechanisms of natural products that target the TME. We also review the effects of natural products used in combination with anticancer agents. Moreover, we highlight nanotechnology and other materials used to enhance the effects of natural products. Overall, our hope is that this review of these natural products will encourage more thoughts and ideas on therapeutic development to benefit lung cancer patients.

A Pharmacokinetic Evaluation of a Pectin-Based Oral Multiparticulate Matrix Carrier of Carbamazepine

Background

Carbamazepine is a drug used in the treatment of neurological disorders such as epilepsy. However, due to its erratic absorption, oral bioavailability is often poor. There is, therefore, the need to develop alternative formulations for carbamazepine with better pharmacokinetic characteristics.

Aim

The aim of this study was to formulate an oral modified-release multiparticulate matrix of carbamazepine from cocoa pod husk (CPH) pectin and evaluate the pharmacokinetic profile of this formulation using in vitro and in vivo models.

Methods

CPH pectin was extracted from cocoa pod husks with hot aqueous and citric acid solutions. Oral multiparticulate carbamazepine matrices were formulated from CPH pectin cross-linked with calcium. The formulation was evaluated for carbamazepine content and release profile in vitro. For in vivo pharmacokinetic profile estimation, rats were put into 4 groups of 5 animals each to receive carbamazepine multiparticulate matrix formulations A and B, carbamazepine powder, and Tegretol CR^®. Animals in each group received 200 mg/kg of each drug via the oral route. Maximum plasma concentration (C_max), area under the concentration-time curve (AUC), elimination rate constant (K_e), and terminal half-life (t_1/2) of the formulations were estimated by noncompartmental analysis.

Results

The pectin extraction from fresh cocoa pod husks using hot aqueous and citric acid solutions gave pectin yields of 9.63% and 11.54%, respectively. The drug content of carbamazepine in CPH pectin formulations A and B was 95% and 96%, respectively. There was controlled and sustained release of carbamazepine for both formulations A and B in vitro. AUC_0⟶36 (176.20 ± 7.97 µg.h/mL), C_max (8.45 ± 0.71 μg/mL), T_max (12 ± 1.28 h), and t_1/2 (13.75 ± 3.28 h) of formulation A showed a moderately enhanced and comparable pharmacokinetic profile to Tegretol CR^® (AUC_0⟶36: 155 ± 7.15 µg.h/mL, C_max: 8.24 ± 0.45 μg/mL, T_max: 8.0 ± 2.23 h, and t_1/2: 13.51 ± 2.87 h).

Conclusion

Findings from the study suggest that formulations of CPH pectin had the potential to control and maintain therapeutic concentrations of carbamazepine in circulation over a period of time in the rat model.

Hydrogel Encapsulation of Lactobacillus casei by Block Charge Modified Pectin and Improved Gastric and Storage Stability

Lactobacillus casei (L. casei W8) was encapsulated in pectin methylesterase (PME) charge modified pectin hydrogels; stability and in vitro release were evaluated under simulated gastrointestinal (GI) conditions. PME, 355 U/mL, de-esterified citrus pectin to 35% from 72% degree of esterification (DE). Pectin ζ-potential decreased to about −37 mV and molecular weight decreased from 177 kDa to 143 kDa during charge modification. More than 99% L. casei W8 were encapsulated in block charged, low methoxy pectin (35 mLMP) hydrogels by calcium ionotropic gelation. The integrity of the hydrogels was maintained under simulated GI conditions, and no release of L. casei W8 was observed. Microbial counts of encapsulated L. casei ranged from 6.94 log CFU/g to 10.89 log CFU/g and were 1.23 log CFU/g higher than for unencapsulated L. casei W8. The viability of encapsulated L. casei W8 in wet hydrogels remained the same for 2 weeks, but nearly all flora died after 4 weeks storage at 4 °C. However, freeze dried hydrogels of L. casei W8 were viable for 42 days at 4 °C and 14 days at room temperature. Charge modified pectin hydrogels are potentially good vehicles for colon-targeted delivery carrier for probiotics and longer stability of L. casei W8.

Biopolymer-based Carriers for DNA Vaccine Design

Over the last 30 years, genetically engineered DNA has been tested as novel vaccination strategy against various diseases, including human immunodeficiency virus (HIV), hepatitis B, several parasites, and cancers. However, the clinical breakthrough of the technique is confined by the low transfection efficacy and immunogenicity of the employed vaccines. Therefore, carrier materials were designed to prevent the rapid degradation and systemic clearance of DNA in the body. In this context, biopolymers are a particularly promising DNA vaccine carrier platform due to their beneficial biochemical and physical characteristics, including biocompatibility, stability, and low toxicity. This article reviews the applications, fabrication, and modification of biopolymers as carrier medium for genetic vaccines.

Development and characterization of novel pectin rafts for the delivery of ibandronate

Bisphosphonates cause irritation of the esophagus and stomach after oral administration. This study was planned to overcome the problems associated with bisphosphonates through the formation of rafts in the stomach and enhance the availability of the drug at the absorption site. A novel pectin raft was developed through the utilization of citrus pectin. The percentage of pectin and profile of neutralization of the raft were investigated. Ibandronate, the polymers and the developed formulation were characterized by Fourier transform infrared spectroscopy (FTIR), X-ray diffraction (XRD), thermogravimetric analysis (TGA) and differential scanning calorimetry (DSC). The release of ibandronate was investigated in 0.1 N hydrochloric acid (HCl), 0.5 N hydrochloric acid, 1.0 N hydrochloric acid and simulated gastric fluid (SGF), and a cell viability study was performed using Caco-2 cells. The RFF5 formulation contained 94.58% pectin, and the duration of neutralization was 45.41 min. The FTIR and XRD showed the chemical stability and uniform distribution of ibandronate in the raft. The TGA and DSC indicated the thermal stability of the formulation. RFF5 showed 99.95% release of ibandronate at 5 min in SGF. RFF5 showed up to 90.47% cell viability when Caco-2 cells were treated with or without the drug (ibandronate). The developed raft can effectively stop the irritation of the stomach and esophagus caused by ibandronate and improve the availability of the drug at the absorption site.

Carbohydrate supplementation: a critical review of recent innovations

PURPOSE

To critically examine the research on novel supplements and strategies designed to enhance carbohydrate delivery and/or availability.

METHODS

Narrative review.

RESULTS

Available data would suggest that there are varying levels of effectiveness based on the supplement/supplementation strategy in question and mechanism of action. Novel carbohydrate supplements including multiple transportable carbohydrate (MTC), modified carbohydrate (MC), and hydrogels (HGEL) have been generally effective at modifying gastric emptying and/or intestinal absorption. Moreover, these effects often correlate with altered fuel utilization patterns and/or glycogen storage. Nevertheless, performance effects differ widely based on supplement and study design. MTC consistently enhances performance, but the magnitude of the effect is yet to be fully elucidated. MC and HGEL seem unlikely to be beneficial when compared to supplementation strategies that align with current sport nutrition recommendations. Combining carbohydrate with other ergogenic substances may, in some cases, result in additive or synergistic effects on metabolism and/or performance; however, data are often lacking and results vary based on the quantity, timing, and inter-individual responses to different treatments. Altering dietary carbohydrate intake likely influences absorption, oxidation, and and/or storage of acutely ingested carbohydrate, but how this affects the ergogenicity of carbohydrate is still mostly unknown.

CONCLUSIONS

In conclusion, novel carbohydrate supplements and strategies alter carbohydrate delivery through various mechanisms. However, more research is needed to determine if/when interventions are ergogenic based on different contexts, populations, and applications.

Nano and microscale delivery platforms for enhanced oral peptide/protein bioavailability

In recent years, peptide/protein drugs have attracted considerable attention owing to their superior targeting and therapeutic effect and fewer side effects compared with chemical drugs. Oral administration modality with enhanced patient compliance is increasingly being recognized as an ideal route for peptide/protein delivery. However, the limited permeation efficiency and low oral bioavailability of peptide/protein drugs significantly hinder therapeutic advances. To address these problems, various nano and microscale delivery platforms have been developed, which offer significant advantages in oral peptide/protein delivery. In this review, we briefly introduce the transport mechanisms of oral peptide/protein delivery and the primary barriers to this delivery process. We also highlight the recent advances in various nano and microscale delivery platforms designed for oral peptide/protein delivery. We then summarize the existing strategies used in these delivery platforms to improve the oral bioavailability and permeation efficiency of peptide/protein therapeutics. Finally, we discuss the major challenges faced when nano and microscale systems are used for oral peptide/protein delivery. This review is expected to provide critical insight into the design and development of oral peptide/protein delivery systems with significant therapeutic advances.

Dual Oral Tissue Adhesive Nanofiber Membranes for pH-Responsive Delivery of Antimicrobial Peptides

Bioadhesive membranes with controllable and reversible underwater adhesion are desirable for several biomedical applications ranging from biosensing, drug/therapeutic delivery, and tissue regeneration. Here, we present dual soft mucosal and hard bone/enamel tissue adhesive nanofiber membranes composed of chitosan and pectin derivatives for pH-controlled delivery of antimicrobial peptides (AMPs) in the oral cavity. Ex vivo testing with porcine esophagus (soft mucosal mimic) indicated a 2-fold increase in the mucoadhesion of chitosan membranes with 0.05 wt % oxidized pectin coating, while the uncoated membranes exhibited 3-4-fold stronger adhesion to hydroxyapatite discs (enamel/hard bone mimic) compared to the coated membranes. The former is attributed to a synergistic interaction of surface nanofiber topography, intermolecular hydrogen bonding, and aldehyde-amine chemistry between surface polar groups and mucosal proteins, while the latter may arise from electrostatic interactions between cationic amines (-NH₃⁺) in chitosan and anionic phosphates (-PO₄^3-) in hydroxyapatite. Further, the dual hard-soft oral tissue adhesive nanofiber membranes loaded with cationic amphipathic AMPs (D-GL13K and IDR-1018) elicited pH-responsive AMP delivery and antimicrobial action comparable to chlorhexidine (CHX) against oral streptococci. Concurrently, the AMP loaded membranes were cytocompatible to both soft epithelial tissue-derived human oral keratinocytes and hard calvarial murine pre-osteoblast cells. We envision these membranes to function as adhesive gingival grafts and guided bone regeneration (GBR) membranes at the hard-soft tissue interface while simultaneously protecting against oral infections.