Preparation and Evaluation of Mucin-Gelatin Mucoadhesive Microspheres for Rectal Delivery of Ceftriaxone Sodium

Microporous/Macroporous Polycaprolactone Scaffolds for Dental Applications

This study leverages the advantages of two fabrication techniques, namely, melt-extrusion-based 3D printing and porogen leaching, to develop multiphasic scaffolds with controllable properties essential for scaffold-guided dental tissue regeneration. Polycaprolactone-salt composites are 3D-printed and salt microparticles within the scaffold struts are leached out, revealing a network of microporosity. Extensive characterization confirms that multiscale scaffolds are highly tuneable in terms of their mechanical properties, degradation kinetics, and surface morphology. It can be seen that the surface roughness of the polycaprolactone scaffolds (9.41 ± 3.01 µm) increases with porogen leaching and the use of larger porogens lead to higher roughness values, reaching 28.75 ± 7.48 µm. Multiscale scaffolds exhibit improved attachment and proliferation of 3T3 fibroblast cells as well as extracellular matrix production, compared with their single-scale counterparts (an approximate 1.5- to 2-fold increase in cellular viability and metabolic activity), suggesting that these structures could potentially lead to improved tissue regeneration due to their favourable and reproducible surface morphology. Finally, various scaffolds designed as a drug delivery device were explored by loading them with the antibiotic drug cefazolin. These studies show that by using a multiphasic scaffold design, a sustained drug release profile can be achieved. The combined results strongly support the further development of these scaffolds for dental tissue regeneration applications.

Purified mucins in drug delivery research

One of the main challenges in the field of drug delivery remains the development of strategies to efficiently transport pharmaceuticals across mucus barriers, which regulate the passage and retention of molecules and particles in all luminal spaces of the body. A thorough understanding of the molecular mechanisms, which govern such selective permeability, is key for achieving efficient translocation of drugs and drug carriers. For this purpose, model systems based on purified mucins can contribute valuable information. In this review, we summarize advances that were made in the field of drug delivery research with such mucin-based model systems: First, we give an overview of mucin purification procedures and discuss the suitability of model systems reconstituted from purified mucins to mimic native mucus. Then, we summarize techniques to study mucin binding. Finally, we highlight approaches that made use of mucins as building blocks for drug delivery platforms or employ mucins as active compounds.

A polymer hybrid film based on poly(vinyl cinnamate) and poly(2-hydroxy ethyl methacrylate) for controlled flurbiprofen release

A crosslinked polymer hybrid film, ipn-poly(vinyl cinnamate-graft-2-hydroxy ethyl methacrylate)-v-poly(ethylene glycol dimethacrylate) was synthesized by UV initiation using poly(vinyl cinnamate) (polyVCi), 2-hydroxy ethyl methacrylate (HEMA) monomer and ethylene glycol dimethacrylate (EGDMA) crosslinker. Benzophenone (Ph₂CO), was used as the photoinitiator. The synthesis was optimized by changing the concentration of HEMA, Ph₂CO, EGDMA, and UV irradiation time. PolyVCi undergoes photocrosslinking by 2 + 2 photocylo addition while the monomer/crosslinker couple, HEMA/EGDMA, undergoes free radical polymerization and crosslinking to form EGDMA crosslinked polyHEMA. Hence, simultaneous interpenetrating polymer network (IPN) formation occurs. The IPN consists of dual network of photocrosslinked polyVCi and EGDMA crosslinked polyHEMA chains. Grafting of HEMA/EGDMA chains on the polyVCi backbone also occur during network formation. The chemical functionalities present in the polyVCi/polyHEMA/polyEGDMA IPN films obtained were characterized by FTIR and SEM analysis. The contact angle measurements show enhanced wettability of the IPN film compared to polyVCi surface. TGA analysis confirms thermal stability of the films. Swelling behavior of the films examined in water and in ethanol reveals the effects of the chemical natures of polyVCi and polyHEMA as well as that of crosslinking on the hydrophilicity of the film. The films were tested as drug release matrices using flurbiprofen. The drug was loaded into the film matrix during IPN formation under UV irradiation. PolyVCi/polyHEMA/polyEGDMA IPN proved to be a suitable release matrix for flurbiprofen demonstrating controlled release behavior and zero-order release kinetics. The release mechanism was confirmed by its Ritger-Peppas “n” value (1.00 to 1.42), which indicates super case II release.

Progress of gelatin-based microspheres (GMSs) as delivery vehicles of drug and cell

Gelatin has various attractive features as biomedical materials, for instance, biocompatibility, low immunogenicity, biodegradability, and ease of manipulation. In recent years, various gelatin-based microspheres (GMSs) have been fabricated with innovative technologies to serve as sustained delivery vehicles of drugs and genetic materials as well as beneficial bacteria. Moreover, GMSs have exhibited promising potentials to act as both cell carriers and 3D scaffold components in tissue engineering and regenerative medicine, which not only exhibit excellent injectability but also could be integrated into a macroscale construct with the laden cells. Herein, we aim to thoroughly summarize the recent progress in the preparations and biomedical applications of GMSs and then to point out the research direction in future. First, various methods for the fabrication of GMSs will be described. Second, the recent use of GMSs in tumor embolization and in the delivery of cells, drugs, and genetic material as well as bacteria will be presented. Finally, several key factors that may enhance the improvement of GMSs were suggested as delivery vehicles.

Gold-Nanocluster-Embedded Mucin Nanoparticles for Photodynamic Therapy and Bioimaging

Effective delivery of a photosensitizer with the ability to trace its eventual progress forms an important aspect in photodynamic therapy (PDT). Further, the delivery mechanism might require possessing the ability to traverse through the complex mucus barrier that offers retention of therapeutic molecules. In this work, gold nanocluster (Au NC)-embedded mucin nanoparticles were synthesized by a rapid green synthetic procedure for application as nanocarriers and to achieve image-guided PDT. The mucin-based nanocarrier exhibited excellent biocompatibility toward normal cells (HEK 293T). The photosensitizer methylene blue (MB) was loaded onto these Au NC-mucin nanoparticles (NPs). HeLa cancer cells were treated with MB-loaded Au NC-mucin nanoparticles under irradiation of 640 nm light. The cell viability assay revealed that the viability of HeLa cells was reduced to 50% after treatment with MB-loaded Au NC-mucin NPs under 640 nm irradiation. The luminescence exhibited by Au NCs in the nanocarrier was applied for tracking the delivery of MB inside the HeLa cells using confocal microscopy. The flow cytometry assays elucidated the mechanism of cell death.

Interactions of salivary mucins and saliva with food proteins: a review

Mucins are long glycoprotein molecules responsible for the gel nature of the mucous layer that covers epithelial surfaces throughout the body. Mucins, as the major salivary proteins, are also important proteins for the food oral processing and digestion. The interactions of salivary mucins and saliva with several food proteins and food protein emulsions, as well as their functional properties related to the food oral processing were reviewed in this paper. The target food proteins of focus were whey proteins (lactoferrin and beta-lactoglobulin) and non-whey proteins (casein, gelatin, galectin/lectin, and proline-rich proteins). Most of the studies suggest that electrostatic attraction (between positively charged food proteins with negatively charged moieties of mucin mainly on glycosylated region of mucin) is the major mode of interaction between them. On the other hand, casein attracts the salivary proteins only via non-covalent interactions due to its naturally self-assembled micellar structure. Moreover, recent studies related to β-lactoglobulin (BLG)-mucin interactions have clarified the importance of hydrophobic as well as hydrophilic interactions, such as hydrogen bonding. Furthermore, in vitro studies between protein emulsions and saliva observed a strong aggregating effect of saliva on caseinate and whey proteins as well as on surfactant-stabilized emulsions. Besides, the sign and the density of the charge on the surface of the protein emulsion droplets contribute significantly to the behavior of the emulsion when mixed with saliva. Other studies also suggested that the interactions between saliva and whey proteins depends on the pH in addition to the flow rate of the saliva. Overall, the role of interactions of food proteins and food protein emulsions with mucin/saliva-proteins in the oral perception, as well as the physicochemical and structural changes of proteins were discussed.

Self-nanoemulsifying drug-delivery systems for potentiated anti-inflammatory activity of diacerein

Background

Effective treatment of osteoarthritis necessitates both symptomatic relief and hindrance of joint degeneration progression. Non-steroidal anti-inflammatory drugs permit symptomatic relief only and can cause mucosal injury in the gut. Before absorption, diacerein (Dcn) is converted into rhein that counteracts cartilage degeneration without affecting prostaglandin production. Yet, low solubility and laxative action of unabsorbed rhein in the colon hindered its use. Thus, enhanced Dcn dissolution would allow absorption at the upper gut improving its bioavailability and possibly abolishing the laxative action.

Methods

Therefore, self-nanoemulsifying drug delivery systems (SNEDDSs) with each of gelucire 44/14 (Glc) and d-α-tocopheryl polyethylene glycol 1000 succinate (TPGS) at different drug:carrier weight ratios of 1:1, 1:2, 1:4, 1:6, 1:8 and 1:10 were prepared by melt method and filled into hard gelatin capsules. The optimized binary systems were selected based on solid state characterization, scanning electron microscopy (SEM) and in vitro evaluation of the prepared SNEDDSs in comparison with their corresponding physical mixtures (PMs) and Dcn. The optimized systems were further examined with respect to their morphology, size distribution and ζ-potential. Moreover, the anti-inflammatory activity of the optimized systems against carrageenan-induced paw edema in rats was assessed through estimation of edema and edema inhibition percentages as well as histopathological examination and immunohistochemical localization of tumor necrosis factor-alpha (TNF-α) and caspase-3.

Results

Significantly (P<0.05) enhanced in vitro drug release was recorded for SNEDDSs with either carrier when compared to Dcn and the corresponding PMs. SNEDDSs based on 1:10 Dcn:Glc and 1:8 Dcn:TPGS showed significantly (P<0.05) reduced edema and inflammation as well as expression of TNF-α and caspase-3 relative to positive control and Dcn pretreated groups.

Conclusion

These SNEDDSs can be represented as potential oral drug delivery systems of Dcn for enhanced dissolution and anti-inflammatory activity against carrageenan-induced paw edema.

Polymer adhesion predictions for oral dosage forms to enhance drug administration safety. Part 3: Review of in vitro and in vivo methods used to predict esophageal adhesion and transit time

The oral cavity is frequently used to administer pharmaceutical drug products. This route of administration is seen as the most accessible for the majority of patients and supports an independent therapy management. For current oral dosage forms under development, the prediction of their unintended mucoadhesive properties and esophageal transit profiles would contribute for future administration safety, as concerns regarding unintended adhesion of solid oral dosage forms (SODF) during oro-esophageal transit still remain. Different in vitro methods that access mucoadhesion of polymers and pharmaceutical preparations have been proposed over the years. The same methods might be used to test non-adhesive systems and contribute for developing safe-to-swallow technologies. Previous works have already investigated the suitability of non-animal derived in vitro methods to assess such properties. The aim of this work was to review the in vitro methodology available in the scientific literature that used animal esophageal tissue to evaluate mucoadhesion and esophageal transit of pharmaceutical preparations. Furthermore, in vivo methodology is also discussed. Since none of the in vitro methods developed are able to mimic the complex swallowing process and oro-esophageal transit, in vivo studies in humans remain as the gold standard.

Biopolymeric Mucin and Synthetic Polymer Analogs: Their Structure, Function and Role in Biomedical Applications

Mucin networks are viscoelastic fibrillar aggregates formed through the complex self-association of biopolymeric glycoprotein chains. The networks form a lubricious, hydrated protective shield along epithelial regions within the human body. The critical role played by mucin networks in impacting the transport properties of biofunctional molecules (e.g., biogenic molecules, probes, nanoparticles), and its effect on bioavailability are well described in the literature. An alternate perspective is provided in this paper, presenting mucin’s complex network structure, and its interdependent functional characteristics in human physiology. We highlight the recent advances that were achieved through the use of mucin in diverse areas of bioengineering applications (e.g., drug delivery, biomedical devices and tissue engineering). Mucin network formation is a highly complex process, driven by wide variety of molecular interactions, and the network possess structural and chemical variations, posing a great challenge to understand mucin’s bulk behavior. Through this review, the prospective potential of polymer based analogs to serve as mucin mimic is suggested. These analog systems, apart from functioning as an artificial model, reducing the current dependency on animal models, can aid in furthering our fundamental understanding of such complex structures.

Covalently-crosslinked mucin biopolymer hydrogels for sustained drug delivery

The sustained delivery of both hydrophobic and hydrophilic drugs from hydrogels has remained a challenge requiring the design and scalable production of complex multifunctional synthetic polymers. Here, we demonstrate that mucin glycoproteins, the gel-forming constituents of native mucus, are suitable for assembly into robust hydrogels capable of facilitating the sustained release of hydrophobic and hydrophilic drugs. Covalently-crosslinked mucin hydrogels were generated via exposure of methacrylated mucin to ultraviolet light in the presence of a free radical photoinitiator. The hydrogels exhibited an elastic modulus similar to that of soft mammalian tissue and were sensitive to proteolytic degradation by pronase. Paclitaxel, a hydrophobic anti-cancer drug, and polymyxin B, a positively-charged hydrophilic antibacterial drug, were retained in the hydrogels and released linearly with time over seven days. After four weeks of drug release, the hydrogels continued to release sufficient amounts of active paclitaxel to reduce HeLa cell viability and sufficient amounts of active polymyxin B to prevent bacterial proliferation. Along with previously-established anti-inflammatory, anti-viral, and hydrocarbon-solubilizing properties of mucin, the results of this study establish mucin as a readily-available, chemically-versatile, naturally-biocompatible alternative to complex multifunctional synthetic polymers as building blocks in the design of biomaterials for sustained drug delivery.

Rectal route in the 21st Century to treat children

The rectal route can be considered a good alternative to the oral route for the paediatric population because these dosage forms are neither to be swallowed nor need to be taste-masked. Rectal forms can also be administered in an emergency to unconscious or vomiting children. Their manufacturing cost is low with excipients generally regarded as safe. Some new formulation strategies, including mucoadhesive gels and suppositories, were introduced to increase patient acceptability. Even if recent paediatric clinical studies have demonstrated the equivalence of the rectal route with others, in order to enable the use of this promising route for the treatment of children in the 21st Century, some effort should be focused on informing and educating parents and care givers. This review is the first ever to address all the aforementioned items, and to list all drugs used in paediatric rectal forms in literature and marketed products in developed countries.

Novel drug delivery system of plant extract for the management of diabetes: an antidiabetic study

CONTEXT

Moringa oleifera leaves have been reported to have antidiabetic, antitumor, hypotensive, anti-inflammatory, and diuretic properties as well as antibiotic, antitryponosomal, hypotensive, and anti-inflammatory activities. They are outstanding source of vitamins A, B, C, and also rich in calcium and protein.

OBJECTIVES

The aim of the study was to formulate Moringa oleifera powdered leaf tablets and to study the in vitro and in vivo properties of the herbal drug from the tablets.

MATERIAL AND METHODS

The Moringa oleifera powdered leaf was formulated into tablets by direct compression. The in vitro properties of the tablets were evaluated in terms of uniformity of weight, hardness, disintegration time, friability and dissolution rate. Also, the in vivo antidiabetic properties of Moringa oleifera tablets were studied using Wistar rats.

RESULTS AND DISCUSSION

The results of the tablets' weight uniformity gave percentage deviation that was below 5%. Tablet disintegration time ranged from 11.50 ± 0.11 to 14.90 ± 0.27 min. The tablets exhibited friability results lower than 2% and exhibited about 82% to 83% release of the extract at 15 min. In vivo antidiabetic studies showed that at 8 hr, about 54.4% and 40% of glucose reduction occurred in groups that received Moringa oleifera tablets and glibenclamide (Daonil®) respectively, while the negative control groups showed increased blood glucose level with time.

CONCLUSIONS

This study has shown that Moringa oleifera leaves formulated into tablets possess good physicochemical and antidiabetic properties in addition to being a supplement.

Formulation Development and Evaluation of Drug Release Kinetics from Colon-Targeted Ibuprofen Tablets Based on Eudragit RL 100-Chitosan Interpolyelectrolyte Complexes

Colon-targeted drug delivery systems (CTDDSs) could be useful for local treatment of inflammatory bowel diseases (IBDs). In this study, various interpolyelectrolyte complexes (IPECs), formed between Eudragit RL100 (EL) and chitosan (CS), by nonstoichiometric method, and tablets based on the IPECs, prepared by wet granulation, were evaluated as potential oral CTDDSs for ibuprofen (IBF). Results obtained showed that the tablets conformed to compendial requirements for acceptance and that CS and EL formed IPECs that showed pH-dependent swelling properties and prolonged the in vitro release of IBF from the tablets in the following descending order: 3 : 2 > 2 : 3 > 1 : 1 ratios of CS and EL. An electrostatic interaction between the carbonyl (–CO–) group of EL and amino (–NH₃⁺) group of CS of the tablets formulated with the IPECs was capable of preventing drug release in the stomach and small intestine and helped in delivering the drug to the colon. Kinetic analysis of drug release profiles showed that the systems predominantly released IBF in a zero-order manner. IPECs based on CS and EL could be exploited successfully for colon-targeted delivery of IBF in the treatment of IBDs.

Matrix-loaded biodegradable gelatin nanoparticles as new approach to improve drug loading and delivery

The long-term objective of this study is to develop a nanoparticulate formulation based on gelatin or its admixtures with other polyelectrolytes, under very gentle nanoprecipitation conditions, for the delivery of fragile macromolecules such as proteins and peptide drugs. However, the objective of the present study was to achieve drug loading into the matrices of gelatin-based nanoparticles through incubation of the drug-gelatin solution prior to formation and cross-linking of the nanoparticles in situ. Two molecular weight types (4 kDa and 20 kDa) of fluorescein isothiocyanate dextran (FITC-D) were used as surrogate macromolecules to study the loading and in vitro release behavior of gelatin nanoparticles. Unloaded and FITC-D-loaded gelatin nanoparticles were prepared by the one-step desolvation technique using ethanol-water mixture as the non-solvent. The preparation method was optimized with respect to the amount of cross-linking agent and cross-linking time. The nanoparticles formed were further characterized for mean size, size distribution and zeta potential using a Zetasizer nano while the morphology of the particles was evaluated by scanning electron microscopy (SEM). For cell uptake studies, FITC-D-labeled nanoparticles were incubated with Caco-2 cell monolayers and then evaluated using fluorescence microscopy. Results obtained showed the formation of very smooth and spherical particles with a unimodal distribution. Zeta potential measurements revealed that both the unloaded and FITC-D-loaded nanoparticles had a surface charge of -23.0 mV at pH 7.0. The loading capacity of the nanoparticles was found to be approximately 93.0 microg FITC-D (20 kDa) and 86 microg FITC-D (4 kDa) per milligram gelatin nanoparticles. Up to 16.5% of the 20 kDa FITC-D was loaded on the surface of the nanoparticles while 76.8% was entrapped into the matrices of the particles. For the 4 kDa FITC-D, 10.8% was bound to the surface of the particles while 75.6% was entrapped into the core of the nanoparticles. The release profile of FITC-D from the nanoparticles over a 168-h period showed a low release in phosphate-buffered saline (PBS), pH 7.4 while more than 80% was released after 3h for both types of FITC-D in PBS containing trypsin. Release of the 4 kDa FITC-D from the nanoparticles was generally more rapid than that of the 20 kDa indicating that its entrapment into gelatin nanoparticles was based on weaker interactions when compared to that of the higher molecular weight FITC-D. Bio-imaging using fluorescence microscopy demonstrated uptake and internalization of the nanoparticles, notably into the nucleus and the cytoplasm, by Caco-2 cells.