The development of injectable gelatin/silk fibroin microspheres for the dual delivery of curcumin and piperine

Physico-Chemical Characterizations of Composited Calcium-Ortho-Phosphate Porous Particles and Their Controlled Release Behavior of Clindamycin Phosphate and Amikacin Sulfate

The porous particles prepared from composited calcium-ortho-phosphate (biphasic), Thai silk fibroin, gelatin, and alginate, with an organic to inorganic component ratio of 15.5:84.5, were tested for their abilities to control the release of the commercialized antibiotic solutions, clindamycin phosphate (CDP) and amikacin sulfate (AMK). The in vitro biodegradability tests complying to the ISO 10993-13:2010 standard showed that the particles degraded <20 wt% within 56 days. The drugs were loaded through a simple adsorption, with the maximum loading of injection-graded drug solution of 43.41 wt% for CDP, and 39.08 wt% for AMK. The release profiles from dissolution tests of the drug-loaded particles varied based on the adsorption methods used. The drug-loaded particles (without a drying step) released the drug immediately, while the drying process after the drug loading resulted in the sustained-release capability of the particles. The model-fitting of drug release profiles showed the release driven by diffusion with the first-ordered kinetic after the initial burst release. The released CDF and AMK from particles could sustain the inhibition of Gram-positive bacteria and Gram-negative bacteria, respectively, for at least 72 h. These results indicated the potential of these composited particles as controlled-release carriers for CDP and AMK.

Hemocompatibility Evaluation of Thai Bombyx mori Silk Fibroin and Its Improvement with Low Molecular Weight Heparin Immobilization

Bombyx mori silk fibroin (SF), from Nangnoi Srisaket 1 Thai strain, has shown potential for various biomedical applications such as wound dressing, a vascular patch, bone substitutes, and controlled release systems. The hemocompatibility of this SF is one of the important characteristics that have impacts on such applications. In this study, the hemocompatibility of Thai SF was investigated and its improvement by low molecular weight heparin (LMWH) immobilization was demonstrated. Endothelial cell proliferation on the SF and LMWH immobilized SF (Hep/SF) samples with or without fibroblast growth factor-2 (FGF-2) was also evaluated. According to hemocompatibility evaluation, Thai SF did not accelerate clotting time, excess stimulate complement and leukocyte activation, and was considered a non-hemolysis material compared to the negative control PTFE sheet. Platelet adhesion of SF film was comparable to that of the PTFE sheet. For hemocompatibility enhancement, LMWH was immobilized successfully and could improve the surface hydrophilicity of SF films. The Hep/SF films demonstrated prolonged clotting time and slightly lower complement and leukocyte activation. However, the Hep/SF films could not suppress platelet adhesion. The Hep/SF films demonstrated endothelial cell proliferation enhancement, particularly with FGF-2 addition. This study provides fundamental information for the further development of Thai SF as a hemocompatible biomaterial.

In vitro biological activities of the flexible and virus nanoparticle-decorated silk fibroin-based films

Flexible films were prepared from silk fibroin (SF) and gelatin (GA) with a presence of glycerol (Gly), followed by water vapor annealing to achieve water-insoluble matrices. The blended SF/GA/Gly films were chemically conjugated with tobacco mosaic virus (TMV), either native (TMV-wt) or genetically modified with Arg-Gly-Asp (RGD) sequences (TMV-rgd), to improve cellular responses. The attachment and proliferation of L929 cells on TMV-decorated films were improved, possibly due to enhanced surface roughness. The cellular responses were pronounced with TMV-rgd, due to the proper decoration of RGD, which is an integrin recognition motif supporting cell binding. However, the biological results were inconclusive for human primary cells because of an innate slow growth kinetic of the cells. Additionally, the cells on SF/GA/Gly films were greater populated in S and G2/M phase, and the cell cycle arrest was notably increased in the TMV-conjugated group. Our findings revealed that the films modified with TMV were cytocompatible and the cellular responses were significantly enhanced when conjugated with its RGD mutants. The biological analysis on the cellular mechanisms in response to TMV is further required to ensure the safety concern of the biomaterials toward clinical translation.

Development of a cellulose-based scaffold for sustained delivery of curcumin

Due to the unique properties of cellulose-based materials, they are attractive to be developed in industrial pharmaceutics and biomedical fields. Carboxymethyl-diethyl amino ethyl cellulose scaffold (CM-DEAEC) has been synthesized in the current work as a smart novel derivative of cellulose with a great functionality in drug delivery systems. The scaffolds were well cross-linked with 2% (v/v) epichlorohydrin (ECH), loaded with curcumin (Cur), and then were analyzed by FT-IR, XRD, SEM, and mechanical strength. While developing the ideal delivery platform, curcumin (an important chemotherapeutic agent) was chosen due to its hydrophobicity and poor bioavailability. Thus, we developed a novel scaffold for efficient loading and controlled releasing of curcumin. The swelling ratio of 136%, high curcumin entrapment efficiency (up to 83.7%), sustained in vitro drug release profile, and appropriate degradability in three weeks confirmed significant properties of the CM-DEAEC scaffold. More than 99% antibacterial activity has been observed by the cross-linked curcumin loaded CM-DEAEC scaffolds. Cytotoxicity studies using 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) assay and 4',6-diamidino-2-phenylindole (DAPI) staining showed that cross-inked curcumin loaded CM-DEAEC scaffolds did not show any toxicity using L929 cells. All experiments were compared with CMC scaffolds and better characteristics of the novel scaffold for drug delivery have been confirmed.

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.

Osteogenic differentiation of rat bone marrow-derived mesenchymal stem cells encapsulated in Thai silk fibroin/collagen hydrogel: a pilot study in vitro

Background

Silk fibroin (SF) can be processed into a hydrogel. SF/collagen hydrogel may be a suitable biomaterial for bone tissue engineering.

Objectives

To investigate in vitro biocompatibility and osteogenic potential of encapsulated rat bone marrow-derived mesenchymal stem cells (rat MSCs) in an injectable Thai SF/collagen hydrogel induced by oleic acid–poloxamer 188 surfactant mixture in an in vitro pilot study.

Methods

Rat MSCs were encapsulated in 3 groups of hydrogel scaffolds (SF, SF with 0.05% collagen [SF/0.05C], and SF with 0.1% collagen [SF/0.1C]) and cultured in a growth medium and an osteogenic induction medium. DNA, alkaline phosphatase (ALP) activity, and calcium were assayed at periodically for up to 5 weeks. After 6 weeks of culture the cells were analyzed by scanning electron microscopy and energy dispersive spectroscopy.

Results

Although SF hydrogel with collagen seems to have less efficiency to encapsulate rat MSCs, their plateau phase growth in all hydrogels was comparable. Inability to maintain cell viability as cell populations declined over 1–5 days was observed. Cell numbers then plateaued and were maintained until day 14 of culture. ALP activity and calcium content of rat MSCs in SF/collagen hydrogels were highest at day 21. An enhancing effect of collagen combined with the hydrogel was observed for proliferation and matrix formation; however, benefits of the combination on osteogenic differentiation and biomineralization are as yet unclear.

Conclusion

Rat MSCs in SF and SF/collagen hydrogels showed osteogenic differentiation. Accordingly, these hydrogels may serve as promising scaffolds for bone tissue engineering.

Thai silk fibroin gelation process enhancing by monohydric and polyhydric alcohols

Silk fibroin hydrogel is an interesting natural material in various biomedical applications. However, the self-assembled gelation takes a long time. In this work, different alcohol types are used as gelation enhancers for aqueous silk fibroin solution. Monohydric alcohols having carbon chain length from C1 to C4 and polyhydric alcohols with the number of mono- to tri- hydroxyl groups were used as the enhancers which are effective for rapid gelation. The addition of monohydric alcohol distinctively reduced the gelation time, comparing to the polyhydric alcohol. The gelation process is directly dependent on the polarity of alcohol and hydrophobicity. The alcohol mediated gelation imparts strong viscoelastic property and enhanced compressive modulus of resulting hydrogels. This is due to the effective formation of self-assembled beta sheet network of the silk fibroin chains facilitates the gelation process.

Production of Curcumin-Loaded Silk Fibroin Nanoparticles for Cancer Therapy

Curcumin, extracted from the rhizome of Curcuma longa, has been widely used in medicine for centuries due to its anti-inflammatory, anti-cancer, anti-oxidant and anti-microbial effects. However, its bioavailability during treatments is poor because of its low solubility in water, slow dissolution rate and rapid intestinal metabolism. For these reasons, improving the therapeutic efficiency of curcumin using nanocarriers (e.g., biopolymer nanoparticles) has been a research focus, to foster delivery of the curcumin inside cells due to their small size and large surface area. Silk fibroin from the Bombyx mori silkworm is a biopolymer characterized by its biocompatibility, biodegradability, amphiphilic chemistry, and excellent mechanical properties in various material formats. These features make silk fibroin nanoparticles useful vehicles for delivering therapeutic drugs, such as curcumin. Curcumin-loaded silk fibroin nanoparticles were synthesized using two procedures (physical adsorption and coprecipitation) more scalable than methods previously described using ionic liquids. The results showed that nanoparticle formulations were 155 to 170 nm in diameter with a zeta potential of approximately -45 mV. The curcumin-loaded silk fibroin nanoparticles obtained by both processing methods were cytotoxic to carcinogenic cells, while not decreasing viability of healthy cells. In the case of tumor cells, curcumin-loaded silk fibroin nanoparticles presented higher efficacy in cytotoxicity against neuroblastoma cells than hepatocarcinoma cells. In conclusion, curcumin-loaded silk fibroin nanoparticles constitute a biodegradable and biocompatible delivery system with the potential to treat tumors by local, long-term sustained drug delivery.

Piperine-mediated drug interactions and formulation strategy for piperine: recent advances and future perspectives

INTRODUCTION

Piperine has various pharmacological effects and can modulate the functional activity of metabolic enzymes and drug transporters. Consequently, there is a great interest in the application of piperine as an alternative medicine or bioavailability enhancer. Areas covered: This review deals with the effects of piperine on metabolizing enzymes and drug transporters. It provides the readers with an update on transporter-mediated and also metabolic enzyme-mediated piperine-drug interactions, with emphasis on its in vivo implications. This article also encompasses recent advances in the formulation approaches and technologies for optimizing the delivery of piperine. Expert opinion: Piperine can influence the pharmacokinetics of coadministered drugs, which may result in a therapeutically beneficial or adverse effect. Given that piperine inhibits or stimulates the activity of metabolic enzymes and transporters depending on the treatment conditions, the clinical significance of piperine-drug interactions should be assessed by varying the dose, dosing frequency, and the duration of treatment. In particular, better understanding the clinical relevance of piperine-drug interactions based on long-term assessments will provide a strong basis for the feasibility and applicability of piperine as a bioenhancer or a health-promoting agent. The development of effective formulations is also critical to facilitate the therapeutic applications of piperine.

Localized delivery of curcumin from injectable gelatin/Thai silk fibroin microspheres for anti-inflammatory treatment of osteoarthritis in a rat model

The previously developed gelatin/silk fibroin microspheres were loaded with curcumin and applied for anti-inflammatory treatment in monosodium iodoacetate (MIA)-induced osteoarthritis (OA) in a rat model. The MIA-induced OA rats received a single intra-articular injection with gelatin or gelatin/silk fibroin (30/70) microspheres encapsulating curcumin. The therapeutic effects of treatment groups [concentration of interleukin-6 (IL-6) in blood serum, radiographic and the histological grading on articular joint] were compared with those of normal saline treated OA and normal rats. The result showed that both microsphere groups reduced the level of IL-6 in serum after 1 week of treatment. The gelatin/silk fibroin (30/70) microspheres encapsulating curcumin delayed the cellular destruction in articular joint and synovial tissue after 8 weeks. The radiographic and histological gradings on articular cartilage lesion and synovial tissue change of rats treated with gelatin/silk fibroin (30/70) microspheres encapsulating curcumin were close to those of the normal rats. It was explained that the slow-degrading gelatin/silk fibroin (30/70) microspheres released curcumin for extended period and showed a prolonged anti-inflammatory effect, compared to the fast-degrading gelatin microspheres. This delivery system of curcumin was suggested to be applied for localized treatment of anti-inflammatory in OA with minimal invasion.

Thai Silk Fibroin/Gelatin Sponges for the Dual Controlled Release of Curcumin and Docosahexaenoic Acid for Anticancer Treatment

In this study, curcumin and/or docosahexaenoic acid (DHA) were encapsulated in Thai silk fibroin/gelatin (SF/G) sponges, prepared at different blending ratios, aimed to be applied as a controlled release system for localized cancer therapy. The SF/G sponges were fabricated by freeze-drying and glutaraldehyde cross-linking techniques. Physicochemical properties of the SF/G sponges were characterized. Then, curcumin and/or DHA were loaded in the sponges by physical adsorption. The encapsulation efficiency and the in vitro release of curcumin and/or DHA from the sponges were evaluated. SF/G sponges could encapsulate curcumin and/or DHA at high encapsulation efficiency. The highly cross-linked and slowly degrading SF/G (50/50) sponge released curcumin and/or DHA at the slowest rate. The in vitro cytotoxicity of the sponges against noncancer cells (L929 mouse fibroblast) and anticancer of curcumin and/or DHA released from the sponges against cervical cancer cells (CaSki) were tested. All sponges were not toxic to L929 mouse fibroblast. The mixed curcumin–DHA at the ratio of 1:4 had the highest inhibiting effect on the growth of CaSki, comparing with the release of curcumin or DHA alone. SF/G sponges could be a potential carrier for dual release of curcumin and DHA for anticancer effect.