Development of diclofenac sodium loaded magnetic nanocarriers of pectin interacted with chitosan for targeted and sustained drug delivery

Versatile functionalization of pectic conjugate: From design to biomedical applications

Pectin exists extensively in nature and has attracted much attention in biological applications for its unique chemical and physical characteristics. Functionalized pectin, especially pectic conjugates, has given many possibilities for pectin to improve its properties and bioactivity as well as to deliver active molecules. To better exploit this strategy of pectic functionalization, this review presents in detail the structural modifications of pectin, different synthetic methods, and design strategies of pectic conjugates involving both traditional chemical and "green" approaches. Here, the research ideas and applications of pectic prodrugs as well as the development of preparation based on pectic conjugates are reviewed, with emphasis on crosslinking systems of functionalized pectin and nanosystems based on self-assembly techniques. We hope this review will provide comprehensive and valuable information for the functionalization and systematization of the pectic conjugate from synthesis to application.

Thiolated pectin-chitosan composites: Potential mucoadhesive drug delivery system with selective cytotoxicity towards colorectal cancer

Mucoadhesive drug delivery systems (DDS) may promote safer chemotherapy for colorectal cancer (CRC) by maximizing local drug distribution and residence time. Carbohydrate polymers, e.g. pectin (P) and chitosan (CS), are potential biomaterials for CRC-targeted DDS due to their gelling ability, mucoadhesive property, colonic digestibility, and anticancer activity. Polymer mucoadhesion is augmentable by thiolation, e.g. pectin to thiolated pectin (TP). Meanwhile, P-CS polyelectrolyte complex has been shown to improve structural stability. Herein, we fabricated, characterized, and evaluated 5-fluorouracil-loaded primary DDS combining TP and CS as a composite (TPCF) through triple crosslinking actions (calcium pectinate, polyelectrolyte complex, disulfide). Combination of these crosslinking yields superior mucoadhesion property relative to single- or dual-crosslinked counterparts, with comparable drug release profile and drug compatibility. PCF and TPCF exhibited targeted cytotoxicity towards HT29 CRC cells with milder cytotoxicity towards HEK293 normal cells. In conclusion, TP-CS composites are promising next-generation mucoadhesive and selectively cytotoxic biomaterials for CRC-targeted DDS.

Chitosan hydrogels in 3D printing for biomedical applications

Tissue engineering and regenerative medicine have entered a new stage of development by the recent progress in biology, material sciences, and particularly an emerging additive manufacturing technique, three-dimensional (3D) printing. 3D printing is an advanced biofabrication technique which can generate patient-specific scaffolds with highly complex geometries while hosting cells and bioactive agents to accelerate tissue regeneration. Chitosan hydrogels themselves have been widely used for various biomedical applications due to its abundant availability, structural features and favorable biological properties; however, the 3D printing of chitosan-based hydrogels is still under early exploration. Therefore, 3D printing technologies represent a new avenue to explore the potential application of chitosan as an ink for 3D printing, or as a coating on other 3D printed scaffolds. The combination of chitosan-based hydrogels and 3D printing holds much promise in the development of next generation biomedical implants.

Magnetic nanotechnology for diclofenac remediation: molecular basis of drug adsorption and neurobehavioral toxicology as a preliminary study for safe application

Diclofenac is a commercial non-steroidal anti-inflammatory drug commonly present as a pollutant in naturally occurring water sources and wastewaters. In this work, the adsorption of diclofenac onto chitosan-coated magnetic nanosystems is proposed as a possible tool for remediation. Experimental and theoretical studies have been carried out to reveal the mechanisms associated with diclofenac interactions among all the components of the nanosystem. Mechanisms are presented, analyzed and discussed. A toxicological study in mice was carried out to evaluate the parameters associated with neurotoxicity of the nanodevice. The elucidation of the mechanisms implied in the adsorption process of diclofenac onto magnetic chitosan nanocomposites suggests that diclofenac remediation from water is possible by adsorption onto chitosan. The strategy innovates the commonly used methodologies for diclofenac remediation from pharmaceutical wastes. This magnetic nanotechnology would not induce damage on the nervous system in a murine model, in case of traces remaining in water sources.

Triamcinolone acetonide loaded-cationic nano-lipoidal formulation for uveitis: Evidences of improved biopharmaceutical performance and anti-inflammatory activity

Topical administration of corticosteroids is the cornerstone treatment of anterior uveitis, but poor corneal penetration and retention cause hindrance in their therapeutic utility. The conventional eye drops are less valuable in conditions where inflammation reaches deeper regions of the eye. Therefore, there is a clear need for an effective drug delivery system, which can increase corticosteroid penetration after topical application. To address this, cationic nanostructured lipid carriers of the drug triamcinolone acetonide (cTA-NLC) were prepared. The cTA-NLC were prepared by a hot microemulsion method and evaluated for drug release, permeation, cell uptake, cytotoxicity, anti-inflammatory activity and ocular irritancy. The cTA-NLC are nanometric in size (< 200 nm), with a zeta potential of about +35 mv and % drug EE of 88 %. The nanocarriers exhibited slow and sustained release of around 84 % in 24 h and transcorneal drug permeation of 51 % in 8 h. The nanocarriers exhibited no cytotoxicity (% cell viability of>90 %). The cell uptake study showed that nanocarriers could retain inside the cells for 24 h. The developed formulation could significantly reduce the TNF-α level in LPS induced inflamed cells. The studies indicated that cTA-NLC could be a promising option for the topical treatment of uveitis.

Self-Assembled Nanoparticles Platform Based on Pectin-Dihydroartemisinin Conjugates for Codelivery of Anticancer Drugs

Natural pectin is an important carrier for delivering drugs in biomedical research, however, there are only a few reports on the preparation of pectin nanoparticles, especially a particle size of below 100 nm with high yield. Here we design pectin-dihydroartemisinin/hydrooxycampothecin nanoparticles (PDC-H NPs) through a self-assembly method. The prepared PDC-H NPs contained hydrophilic part of pectin and hydrophobic anticancer drugs of dihydroartemisinin and hydroxycamptothecin, which could increase drug loading, improve water solubility, and achieve controlled release of drugs. The results indicated that the particle size of PDC-H NPs was about 70 nm, drug-loaded efficiency of DHA was 20.33 wt %, and encapsulation efficiency of HCPT was 14.11 wt %. PDC-H NPs exhibited a higher cytotoxicity, the blood retention time of PDC-H NPs was 4.8-fold longer than DHA and was 6.8-fold longer than HCPT. In addition, effective cellular uptake exhibited an obvious synergistic effect compared with DHA and HCPT. 4T1 tumor-bearing mice also showed a higher survival rate than free DHA and free HCPT. The result show that the self-assembled PDC-H NPs is a promising anticancer drug for codelivery.

Xerogel modified diatomaceous earth microparticles for controlled drug release studies

An alternative facile approach for the surface modification of naturally available diatoms with xerogel for controlled drug release applications.

Biocompatible microcrystalline cellulose particles from cotton wool and magnetization via a simple in situ co-precipitation method

This investigation describes the preparation of magnetically doped degradable microcrystalline cellulose (MCC) nanocomposite particles with application potential in biotechnology, solid support for biomolecule/water purification, oil recovery from water and beyond. MCC was first extracted from cotton wool, the most abundant biocompatible polymer, by sulfuric acid hydrolysis and the effect of acid strength was examined. The size of the elongated fiber structure was reduced with increasing acid strength. MCC particles extracted by treatment with 70% sulfuric acid were used to prepare magnetic MCC nanocomposite particles. The nanocomposite particles named as MCC/Fe₃O₄ were prepared via in situ co-precipitation of Fe⁺³/Fe⁺² from their alkaline solution. The precipitated Fe₃O₄ nanoparticles are expected to be bonded with MCC particles via hydrogen bonding. The nanocomposite dispersion was colloidally stable and the particles responded when external magnetic field was applied. It was possible to control the magnetic property by regulating the content of iron oxide.

Functionalized Polymers for Enhance Oral Bioavailability of Sensitive Molecules

Currently, many sensitive molecules have been studied for effective oral administration. These substances are biologically active compounds that mainly suffer early degradation in the gastrointestinal tract (GIT) and physicochemical instability, inactivation and poor solubility and permeability. The sensibility of the biomolecules has limited their oral administration in the body and today is an important research topic to achieve desired effects in medicine field. Under this perspective, various enhancement approaches have been studied as alternatives to increase their oral bioavailability. Some of these strategies include functionalized polymers to provide specific useful benefits as protection to the intestinal tract by preventing its degradation by stomach enzymes, to increase their absorption, permeability, stability, and to make a proper release in the GIT. Due to specific chemical groups, shapes and sizes, morphologies, mechanical properties, and degradation, recent advances in functionalized polymers have opened the door to great possibilities to improve the physicochemical characteristics of these biopharmaceuticals. Today, many biomolecules are found in basic studies, preclinical steps, and others are late stage clinical development. This review summarizes the contribution of functionalized polymers to enhance oral bioavailability of sensitive molecules and their application status in medicine for different diseases. Future trends of these polymers and their possible uses to achieve different formulation goals for oral delivery are also covered in this manuscript.

Preparation and application of micro/nanoparticles based on natural polysaccharides

Polysaccharides have attracted more and more attentions and been recognized to be the most promising materials in recent years because of their outstanding merits such as easily available, non-toxic, biocompatible, biodegradable, and easily modified. Considerable research efforts have been directed toward developing polysaccharides-based micro/nanoparticles (PM/NPs). The new major studies of PM/NPs over the past few years are outlined in this review. Methods of preparation, including self-assembly, ionic-gelation, complex coacervation, emulsification, and desolvation method and some others, are summarized. Different applications of PM/NPs in the field of drug-delivery system are highlighted. Besides, another novel application of PM/NPs that are used as emulsifiers to stabilize Pickering emulsion is also introduced. These environmental-friendly particle emulsifiers have received reasonable attention due to their novel applications, especially in food, cosmetics, and pharmaceutics. From literature surveys, we realized that studies on PM/NP systems for different applications have increased rapidly. Hence, the present review is timely.

Characterization of novel lactoferrin loaded capsules prepared with polyelectrolyte complexes

Novel capsules loaded with lactoferrin (LF) were prepared using polyelectrolyte complexes that were formed by water soluble chitosan (WSC), sodium cellulose sulfate (NaCS) and sodium polyphosphate (PPS). Normal chitosan (soluble in acidic conditions) was chosen as a control to prepare similar capsules with NaCS and PPS. (1)H NMR and FTIR spectra analysis showed that WSC was in a form of chitosan hydrochloride which can be directly dissolved and protonated in acid-free water. SEM results showed that the capsules had a typical wall-capsule structure with a regular spherical shape and an average diameter of 1.97 mm. TGA studies revealed that the thermal stability of the capsules were enhanced and the moisture content of the drug-free/loaded capsules were 6.3% and 3.2%. SDS-PAGE results showed that the primary structures of the processed LF in the capsules were unchanged. Drug loading (LE%) and encapsulation efficiency (EE%) analysis showed that the capsules had a higher LE% (45.6%) and EE% (70.7%) than that of the control. In vitro release studies showed that the capsules had a regular and sustainable release profiles in simulated colonic fluid. All of these results indicated that the capsules prepared could be used as a candidate protein drug carrier for colon.

pH-sensitive microparticles for oral drug delivery based on alginate/oligochitosan/Eudragit(®) L100-55 "sandwich" polyelectrolyte complex

The primary objective of this study was to investigate the influence of the oligochitosan-Eudragit(®) L100-55 polyelectrolyte complex (OCH-EL PEC) on the pH-sensitivity of Eudragit(®) L100-55-treated alginate-oligochitosan microparticles. In order to achieve this, three types of naproxen-loaded microparticles were prepared under mild and environmentally friendly conditions using a custom made device with coaxial air flow: Ca-alginate (Ca-ALG), alginate-oligochitosan (ALG-OCH) and alginate-oligochitosan-Eudragit(®) L100-55 (ALG-OCH-EL) microparticles. After drying, the microparticles were subjected to microscopic analysis, and physicochemical and biopharmaceutical characterization. The non-covalent interaction between OCH and EL and the formation of OCH-EL PEC during the preparation procedure of the particles were verified by thermal and FT-IR analysis. The obtained particles exhibited acceptable sphericity and surface roughness due to the presence of the drug crystals (Ca-ALG particles) and OCH-EL PEC (ALG-OCH-EL particles). It was found that reinforcement of the ALG-OCH particles with OCH-EL PEC had no significant effect on the relatively high encapsulation efficiencies (>74.4%). The results of drug release studies confirmed the ability of ALG-OCH PEC to sustain drug release at pH 6.8 and 7.4. However, this PEC showed enhanced sensitivity to an acidic environment and to simulated intestinal fluid (pH 6.8) after prior exposure to an acidic medium. Additional treatment of ALG-OCH particles with EL and formation of "sandwich" ALG-OCH-EL PEC was essential not only to improve stability and decrease drug release in acidic medium, but also to achieve sustained release after the pH of dissolution medium was raised to 6.8. The obtained results suggested that ALG-OCH-EL microparticles have promising potential as pH-sensitive multiparticulate drug carriers for oral delivery of NSAIDs.