Oral Delivery of Curcumin Using Silk Nano- and Microparticles

Silk fibroin microspheres loaded Rehmannia Liuwei extract for the protection of endothelial cells from the inhibitory effects

Liuwei Dihuang (LWDH) is a multi-component and multi-target Chinese herbal compound widely used for treating chronic conditions such as diabetes, diabetic nephropathy, hypertension, osteoporosis, and chronic kidney disease. However, traditional Chinese medicine (TCM) preparations like decoction and pill face limitations, including low active component concentration, limited bioavailability, short half-life, and the need for high dosage, which may increase the burden on liver and kidney functions and reduce clinical efficacy. In this study, LWDH was further purified using D101 macroporous adsorption resin, resulting in a soluble extract with an active component content 53.6 times higher than that of LWDH itself. The freeze-dried LWDH extract was then encapsulated within silk fibroin (SF) microspheres to significantly enhance the sustained release performance of the drug. In a human umbilical vein endothelial cell (HUVEC) model cultured under high glucose conditions, methanol vapor-treated SF/LWDH microspheres demonstrated a decrease in the 24-hour drug release rate from 61.88 % to 34.81 %, augmenting their protective effect on endothelial cells.

Unveiling the synergy: Biocompatible alginate-cellulose hydrogel loaded with silk fibroin and zinc ferrite nanoparticles for enhanced cell adhesion, and anti-biofilm activity

Combining a biocompatible hydrogel scaffold with the cell-supportive properties of silk fibroin (SF) and the unique functionalities of ZnFe2O4 nanoparticles creates a promising platform for advanced nanobiomaterials. The research is centered on synthesizing a natural hydrogel using cellulose (Cellul) and sodium alginate (SA) combined with SF and zinc ferrite nanoparticles. A range of analytical and biological assays were conducted to determine the biological and physicochemical properties of the nanobiocomposite. The hemolysis and 2,5-diphenyl-2H-tetrazolium bromide (MTT) assays indicated that the SA-Cellul hydrogel/SF/ZnFe2O4 nanobiocomposite was a biocompatible against human dermal fibroblasts (Hu02) and red blood cells (RBC). In addition, aside from demonstrating outstanding anti-biofilm activity, the nanobiocomposite also promotes the Hu02 cells adhesion, showcasing the synergistic effect of incorporating SF and ZnFe2O4 nanoparticle. These promising results show that this nanobiocomposite has potential applications in various biomedical fields.

Homeopathic Formulations of Syzygium jambolanum Alleviate Glycation-Mediated Structural and Functional Modifications of Albumin: Evaluation through Multi-Spectroscopic and Microscopic Approaches

BACKGROUND

 The growing interest in identifying the mode of action of traditional medicines has strengthened its research. Syzygium jambolanum (Syzyg) is commonly prescribed in homeopathy and is a rich source of phytochemicals.

OBJECTIVE

 The present study aims to shed light on the anti-glycation molecular mechanism of Syzyg mother tincture (MT), 30c, and 200c on glycated human serum albumin (HSA) by multi-spectroscopic and microscopic approaches.

METHODS

 The phytochemicals and antioxidant potential of the Syzyg formulations were estimated by the high-performance liquid chromatography and spectroscopic technique, respectively. Glycation was initiated by incubating HSA with methylglyoxal, three Syzyg formulations, and the known inhibitor aminoguanidine in separate tubes at 37°C for 48 hours. The formation of glycation adducts was assessed by spectrofluorometer and affinity chromatography. The structural modifications were analyzed through circular dichroism, Fourier transform infrared spectroscopy, turbidity, 8-anilinonapthalene-1-sulfonic acid fluorescence, and nuclear magnetic resonance. Further, the formation of the aggregates was examined by thioflavin T, native-polyacrylamide gel electrophoresis, and transmission electron microscopy. Additionally, the functional modifications of glycated HSA were determined by esterase-like activity and antioxidant capacity. The binding analysis of Syzyg formulations with glycated HSA was evaluated by surface plasmon resonance (SPR).

RESULTS

 Syzyg formulations MT, 30c, and 200c contained gallic acid and ellagic acid as major phytochemicals, with concentrations of 16.02, 0.86, and 0.52 µg/mL, and 227.35, 1.35, and 0.84 µg/mL, respectively. Additionally, all three formulations had remarkable radical scavenging ability and could significantly inhibit glycation compared with aminoguanidine. Further, Syzyg formulations inhibited albumin's structural and functional modifications. SPR data showed that Syzyg formulations bind to glycated HSA with an equilibrium dissociation constant of 1.10 nM.

CONCLUSION

 Syzyg formulations inhibited the glycation process while maintaining the structural and functional integrity of HSA.

Colon-targeted hydroxyethyl starch-curcumin microspheres with high loading capacity ameliorate ulcerative colitis via alleviating oxidative stress, regulating inflammation, and modulating gut microbiota

Curcumin (CUR) is a natural polyphenol that holds promise for treating ulcerative colitis (UC), yet oral administration of CUR exhibits limited bioavailability and existing formulations for oral delivery of CUR often suffer from unsatisfactory loading capacity. This study presents hydroxyethyl starch-curcumin microspheres (HC-MSs) with excellent CUR loading capacity (54.52 %), and the HC-MSs can further encapsulate anti-inflammatory drugs dexamethasone (DEX) to obtain a combination formulation (DHC-MSs) with high DEX loading capacity (19.91 %), for combination therapy of UC. The microspheres were successfully engineered, retaining the anti-oxidative and anti-inflammatory activities of parental CUR and demonstrating excellent biocompatibility and controlled release properties, notably triggered by α-amylase, facilitating targeted drug delivery to inflamed sites. In a mouse UC model induced by dextran sulfate sodium, the microspheres effectively accumulated in inflamed colons and both HC-MSs and DHC-MSs exhibited superior therapeutic efficacy in alleviating UC symptoms compared to free DEX. Moreover, mechanistic exploration uncovered the multifaceted therapeutic mechanisms of these formulations, encompassing anti-inflammatory actions, mitigation of spleen enlargement, and modulation of gut microbiota composition. These findings underscore the potential of HC-MSs and DHC-MSs as promising formulations for UC, with implications for advancing treatment modalities for various inflammatory bowel disorders.

Design and fabrication of a magnetic nanobiocomposite based on flaxseed mucilage hydrogel and silk fibroin for biomedical and in-vitro hyperthermia applications

In this research work, a magnetic nanobiocomposite is designed and presented based on the extraction of flaxseed mucilage hydrogel, silk fibroin (SF), and Fe3O4 magnetic nanoparticles (Fe3O4 MNPs). The physiochemical features of magnetic flaxseed mucilage hydrogel/SF nanobiocomposite are evaluated by FT-IR, EDX, FE-SEM, TEM, XRD, VSM, and TG technical analyses. In addition to chemical characterization, given its natural-based composition, the in-vitro cytotoxicity and hemolysis assays are studied and the results are considerable. Following the use of highest concentration of magnetic flaxseed mucilage hydrogel/SF nanobiocomposite (1.75 mg/mL) and the cell viability percentage of two different cell lines including normal HEK293T cells (95.73%, 96.19%) and breast cancer BT549 cells (87.32%, 86.9%) in 2 and 3 days, it can be inferred that this magnetic nanobiocomposite is biocompatible with HEK293T cells and can inhibit the growth of BT549 cell lines. Besides, observing less than 5% of hemolytic effect can confirm its hemocompatibility. Furthermore, the high specific absorption rate value (107.8 W/g) at 200 kHz is generated by a determined concentration of this nanobiocomposite (1 mg/mL). According to these biological assays, this magnetic responsive cytocompatible composite can be contemplated as a high-potent substrate for further biomedical applications like magnetic hyperthermia treatment and tissue engineering.

Curcumin-loaded albumin submicron particles with potential as a cancer therapy: an in vitro study

Curcumin (CUR), a polyphenolic compound, shows promising biological properties, particularly antioxidant activity. However, its medical applications are limited due to its low water solubility, bioavailability, and pH-instability. CUR-loaded albumin microparticles (CUR-HSA-MPs) of submicron size in the range of 800 to 900 nm and a zeta potential of -15 mV were prepared. The CUR loading efficiency was up to 65%. A maximum release of 37% of the encapsulated CUR was observed within 6 h when the CUR-HSA-MPs were dispersed in 50% ethanol in PBS at pH 7, while in RPMI 1640 medium the release was 7%. This demonstrates a sustainable release. The in vitro cytotoxicity of CUR-HSA-MPs showed promising anticancer potential against human hepatocellular carcinoma (Huh-7) and human breast adenocarcinoma (MCF-7) cell lines, although this effect was less pronounced in human dermal fibroblasts (HDFB) and human cholangiocyte (MMN) cell lines. Confocal microscopy was used to confirm the uptake of CUR-HSA-MPs by cancer cells. Our studies revealed that HSA-MPs are potentially promising vehicles for increasing the solubility and bioavailability of CUR.

Curcumin and analogues against head and neck cancer: From drug delivery to molecular mechanisms

BACKGROUND

Head and neck squamous cell carcinoma (HNSCC) is one of the most life-threatening diseases which also causes economic burden worldwide. To overcome the limitations of traditional therapies, investigation into alternative adjuvant treatments is crucial.

PURPOSE

Curcumin, a turmeric-derived compound, demonstrates significant therapeutic potential in diverse diseases, including cancer. Furthermore, research focuses on curcumin analogues and novel drug delivery systems, offering approaches for improved efficacy. This review aims to provide a comprehensive overview of curcumin's current findings, emphasizing its mechanisms of anti-HNSCC effects and potential for clinical application.

METHOD

An electronic search of Web of Science, MEDLINE, and Embase was conducted to identify literature about the application of curcumin or analogues in HNSCC. Titles and abstracts were screened to identify potentially eligible studies. Full-text articles will be obtained and independently evaluated by two authors to make the decision of inclusion in the review.

RESULTS

Curcumin's clinical application is hindered by poor bioavailability, prompting the exploration of methods to enhance it, such as curcumin analogues and novel drug delivery systems. Curcumin could exhibit anti-cancer effects by targeting cancer cells and modulating the tumor microenvironment in HNSCC. Mechanisms of action include cell cycle arrest, apoptosis promotion, reactive oxygen species induction, endoplasmic reticulum stress, inhibition of epithelial-mesenchymal transition, attenuation of extracellular matrix degradation, and modulation of tumor metabolism in HNSCC cells. Curcumin also targets various components of the tumor microenvironment, including cancer-associated fibroblasts, innate and adaptive immunity, and lymphovascular niches. Furthermore, curcumin enhances the anti-cancer effects of other drugs as adjunctive therapy. Two clinical trials report its potential clinical applications in treating HNSCC.

CONCLUSION

Curcumin has demonstrated therapeutic potential in HNSCC through in vitro and in vivo studies. Its effectiveness is attributed to its ability to modulate cancer cells and interact with the intricate tumor microenvironment. The development of curcumin analogues and novel drug delivery systems has shown promise in improving its bioavailability, thereby expanding its clinical applications. Further research and exploration in this area hold great potential for harnessing the full therapeutic benefits of curcumin in HNSCC treatment.

Stabilization and Sustained Release of Fragrances Using Silk-PEG Microspheres

Fragrances, which are commonly used in food, textiles, consumer products, and medical supplies, are volatile compounds that require stabilization and controlled release due to their sensitivity to environmental conditions such as light, oxygen, temperature, and humidity. Encapsulation in various material matrices is a desired technique for these purposes, and there is a growing interest in using sustainable natural materials to reduce environmental impact. In this study, fragrance encapsulation in microspheres made from silk fibroin (SF) was investigated. Fragrance-loaded silk fibroin microspheres (Fr-SFMSs) were prepared by adding fragrance/surfactant emulsions to silk solutions, followed by mixing them with polyethylene glycol under ambient conditions. The study investigated eight different fragrances, where citral, beta-ionone, and eugenol showed higher binding affinities to silk than the other five fragrances, resulting in better microsphere formation with uniform sizes and higher fragrance loading (10-30%). Citral-SFMSs showed characteristic crystalline β-sheet structures of SF, high thermal stability (initial weight loss at 255 °C), long shelf life at 37 °C (>60 days), and sustained release (∼30% of citral remained after incubation at 60 °C for 24 h). When citral-SFMSs with different sizes were used to treat cotton fabrics, about 80% of the fragrance remained on the fabrics after one wash, and the duration of release from the treated fabrics was significantly longer than that of control samples treated with citral alone (no microspheres). This method of preparing Fr-SFMSs has potential applications in textile finishing, cosmetics, and the food industry.

Woven Vascular Stent-Grafts with Surface Modification of Silk Fibroin-Based Paclitaxel/Metformin Microspheres

In-stent restenosis caused by tumor ingrowth increases the risk of secondary surgery for patients with abdominal aortic aneurysms (AAA) because conventional vascular stent grafts suffer from mechanical fatigue, thrombosis, and endothelial hyperplasia. For that, we report a woven vascular stent-graft with robust mechanical properties, biocompatibility, and drug delivery functions to inhibit thrombosis and the growth of AAA. Paclitaxel (PTX)/metformin (MET)-loaded silk fibroin (SF) microspheres were self-assembly synthesized by emulsification-precipitation technology and layer-by-layer coated on the surface of a woven stent via electrostatic bonding. The woven vascular stent-graft before and after coating drug-loaded membranes were characterized and analyzed systematically. The results show that small-sized drug-loaded microspheres increased the specific surface area and promoted the dissolution/release of drugs. The stent-grafts with drug-loaded membranes exhibited a slow drug-release profile more for than 70 h and low water permeability at 158.33 ± 17.56 mL/cm²·min. The combination of PTX and MET inhibited the growth of human umbilical vein endothelial cells. Therefore, it was possible to generate dual-drug-loaded woven vascular stent-grafts to achieve the more effective treatment of AAA.

Improved Stability and In Vitro Anti-Arthritis Bioactivity of Curcumin-Casein Nanoparticles by Ultrasound-Driven Encapsulation

Curcumin possesses beneficial biological functions, namely anti-inflammation and anti-diabetic functions. However, due to its low solubility and crystallinity, its applications are limited. In this work, curcumin was encapsulated in casein micelles in order to form curcumin-casein nanoparticles by ultrasound treatment (5 min). The ultrasound treatment induced the entry of the hydrophobic groups to the inner micelles and the polar sulfydryl groups to the surface of the micelles in order to form compact curcumin-casein nanoparticles of an appropriate size (100-120 nm) for cellular endocytosis. The product exhibited excellent stability during 8 months of cold storage, 6 days at room temperature, and 2 days at body temperature. Advanced in vitro experiments demonstrated that curcumin-casein nanoparticles displayed significantly greater inhibitory activity against the proliferation and proinflammatory cytokines of human fibroblast-like synoviocyte-osteo arthritis (HFLS-OA) cells and HFLS-rheumatoid (RA) cells than native curcumin due to better cellular uptake as a result of the low crystallinity and the appropriate nano-size of the nano-form. The results provide a reference for the use of ultrasound treatment to encapsulate other drug molecules and curcumin-casein nanoparticles as potential treatment for arthritis.

Curcumin-Loaded Self-Assembly Constructed by Octenylsuccinate Fish (Cyprinus carpio L.) Scale Gelatin: Preparation and Characterization

Curcumin loaded octenylsuccinate fish scale gelatin (OFSG) was prepared in this study, to explore the potential of FSG for delivering hydrophobic nutrients. The effects of molecule weight (M_w, 22,677-369 g/mol) and degree of substitution (DS, 0-0.116) on the curcumin loading efficiency (CLE, μg/mL) of OFSG (6.98-26.85 mg/mL) were evaluated. The expose of interior hydrophobic groups in FSG and increased intermolecular hydrophobic area contributed to the loading of curcumin in two phases, respectively. The interaction between OFSG and curcumin showed a decreased absorption in FTIR and an increased crystallinity in XRD. The loading of curcumin into OFSG caused a significant decrease of the particle size (from 350-12,070 to 139-214 nm), PDI (from 0.584-0.659 to 0.248-0.347) and ζ-potential (-12.2 or -11.4 to -21.0 or -20.3). OFSG showed a significantly higher stability and lower release of curcumin than FSG at the end of the simulated gastrointestinal digestion. Thus, OFSG showed great potential in the construction of a carrier for hydrophobic nutrients.

Multi-functional Calotropis gigantea fabric using self-assembly silk fibroin, chitosan and nano-silver microspheres with oxygen low-temperature plasma treatment

The present paper describes a novel multi-functional Calotropis gigantea (CG) fabric with durable antibacterial property and comfortable wearability for various applications. First, antibacterial microspheres (AMs) were prepared by self-assembly of silk fibroin (SF), chitosan (CS) and nano-silver microspheres (NSMs). Oxygen low-temperature plasma (OLTP) treatment was used to improve the adhesion between AMs and CG yarn. The AMs modified CG fabric has soft hand feeling, high moisture regain (10.37 ± 1.87%), good breathability, strong wrinkle resistance, and durable antibacterial properties. The antibacterial rate of the modified CG fabric against Escherichia coli (E. Coil) and Staphylococcus aureus (S. Aureus) is as high as 99.9 ± 0.1%, and it still has an antibacterial activity after washing 20 times (90.24 ± 0.65% and 80.25 ± 1.14%, respectively). The in vivo biocompatibility test showed clear signs of angiogenesis at the implantation site in the rats. Thus, this study offers the foundation for the development of functional CG fiber-based biomedical textiles.

Trends in advanced oral drug delivery system for curcumin: A systematic review

Although curcumin is globally recognized for its health benefits, its clinical application has been restricted by its poor aqueous solubility and stability. To overcome these limitations, nanocarrier-based drug delivery systems (NDS) are one of the most effective approaches being extensively explored over the last few decades to improve curcumin's physicochemical and pharmacological effects. Various NDS could provide productive platforms for addressing the formulation challenge of curcumin, but evidence of such systems has not been summarized. This study aimed to systematically review current evidence of lipid and polymer-based NDS for an oral delivery of curcumin focusing on in vivo models and clinical studies. Among the 48 included studies, 3 studies were randomized controlled clinical trials, while 45 studies were animal models. To date, only five curcumin NDS have been studied in healthy volunteers: γ-cyclodextrin, phytosome, liposome, microemulsion and solid dispersion, while most curcumin NDS have been studied in animal models. Most included studies found that NDS could increase oral bioavailability of curcumin as compared to free curcumin. In conclusion, this systematic review showed evidence of the positive effect of NDS for enhancement of oral bioavailability of curcumin. EXECUTIVE SUMMARY: Curcumin is globally recognized for its health benefits, but its clinical application has been limited by its poor aqueous solubility and stability, which causes poor absorption in the gastrointestinal tract (GI tract) via oral administration. Nanocarrier-based drug delivery systems (NDS) are considered as a productive platform to solve the formulation challenge of curcumin, but evidence of such systems has not been summarized. This study aimed to systematically review current evidence of lipid and polymer-based NDS for an oral delivery of curcumin focusing on in vivo models and clinical studies. Overall, most studies found that all studied NDS could increase the absorption of curcumin as compared to free curcumin. Curcumin was rapidly absorbed and exhibited a long residence time after oral administration of curcumin NDS. In summary, this systematic review showed positive impacts of NDS for enhancement of oral absorption of curcumin.

3-O-Ethyl-L-Ascorbic Acid Doped Enteric-Coated Gelatin Capsules towards the Advanced Oral Curcumin Delivery for Cancers

Among plant-derived polyphenols, curcumin has been recognized as a therapeutically potent nutrient presenting pleiotropic pharmacological effects on various cancers. However, the poor absorption and bioavailability of curcumin limit the use of this excellent naturally occurring polyphenol. 3-O-ethyl-L-ascorbic acid (EA) doped enteric-coated gelatin capsules were studied in the search for advanced oral curcumin delivery. The EA doped enteric-coated gelatin capsules were successfully created based on a developed inner dual enteric coating technique. When placed in four buffer solutions with different pHs (pH 2.0, 5.0, 6.0, and 7.3), the coated gelatin capsules showed delayed-release profiles of curcumin below pH 6.0. In contrast, both pristine and fabricated gelatin capsules showed similar curcumin release profiles at pH 7.3, which is a common pH observed in the lower gastrointestinal tract, especially intestinal regions. In conclusion, these results demonstrated the potential of the EA doped enteric-coated gelatin capsules in developing advanced oral delivery of curcumin targeting intestinal-specific regions.

Animal protein-plant protein composite nanospheres for dual-drug loading and synergistic cancer therapy

The co-delivery of multiple drugs using one drug carrier is a viable strategy to optimize drug dosage and reduce the side effects in chemotherapy. Herein, a hydrophilic animal protein (silk fibroin) and a hydrophobic plant protein (zein) were selected for preparing a composite drug carrier. Adapting our previously developed method for the preparation of regenerated silk fibroin (RSF) nanospheres, we prepared RSF/zein nanospheres that displayed an interesting structure including a single central hole. The particle size of the RSF/zein nanospheres was regulated from 150 to 460 nm by varying the preparation conditions, implying that such a drug carrier is suitable for both intravenous administration and lymphatic chemotherapy. Two anti-cancer drugs with different target sites, paclitaxel (PTX) and curcumin (CUR), were selected for the preparation of dual-drug-loaded CUR/PTX@RSF/zein nanospheres. Both drugs achieved a high loading capacity in the RSF/zein nanospheres, i.e., 8.2% for PTX and 12.1% for CUR. Subsequently, the encapsulated PTX and CUR were released from the RSF/zein nanospheres in a sustained manner for at least 7 days. Importantly, these dual-drug-loaded RSF/zein nanospheres exhibited a considerable synergistic therapeutic effect, showing more efficient suppression of in vitro cancer cell growth than free PTX or CUR, a combination of free PTX and CUR, or single-drug-loaded nanospheres. Therefore, the CUR/PTX@RSF/zein nanospheres developed in this study hold great potential for combination chemotherapy in future clinical applications.

Protein nanoparticles directed cancer imaging and therapy

Cancer has been a serious threat to human health. Among drug delivery carriers, protein nanoparticles are unique because of their mild and environmentally friendly preparation methods. They also inherit desired characteristics from natural proteins, such as biocompatibility and biodegradability. Therefore, they have solved some problems inherent to inorganic nanocarriers such as poor biocompatibility. Also, the surface groups and cavity of protein nanoparticles allow for easy surface modification and drug loading. Besides, protein nanoparticles can be combined with inorganic nanoparticles or contrast agents to form multifunctional theranostic platforms. This review introduces representative protein nanoparticles applicable in cancer theranostics, including virus-like particles, albumin nanoparticles, silk protein nanoparticles, and ferritin nanoparticles. It also describes the common methods for preparing them. It then critically analyzes the use of a variety of protein nanoparticles in improved cancer imaging and therapy.

Miniatured Fluidics-Mediated Modular Self-Assembly of Anticancer Drug-Amino Acid Composite Microbowls for Combined Chemo-Photodynamic Therapy in Glioma

A particulate carrier with the ability to load a combination of therapeutic molecules acting via diverse modes to initiate cancer cell ablation would help heighten anticancer therapeutic outcomes and mitigate harmful side effects due to high doses of mono drug therapy. Moving a step closer, herein, we have developed doxorubicin-curcumin-amino acid-based composite microbowls (CMBs) following miniaturized fluid flow-based self-assembly. The CMBs were further exploited as dual chemo-photodynamic therapeutic agents in C6 glioma cells cultured in both two-dimensional (2D) monolayer and as three-dimensional (3D) spheroids. These CMBs showed synergistic and visible (blue)-light-sensitive cell-killing effects in both C6 cells and 3D spheroids. Furthermore, these bowl-shaped structures also demonstrated good stability and excellent in vitro cytocompatibility in C6 glioma cells. Our results indicated that CMBs with asymmetric cavities could potentially be used as a combinatorial drug carrier enabling simultaneous chemo- and phototherapy for effective cancer treatment. The use of blue light, from the visible part of the electromagnetic system, to generate the phototherapeutic effect further advocates for the ease and widespread applicability of the systems.

Design and synthesis of curcumin nanostructures: Evaluation of solubility, stability, antibacterial and antioxidant activities

By coupling a quaternary pyridinium compound and curcumin (CM), a new antimicrobial agent called CP was obtained. The poor water-solubility was the most important limiting factor in the use of CM and CP. To address this problem, a hydrophilic hyperbranched polyglycerol (PG) was synthesized and reacted with CM and CP via Schiff base reaction to form two new macromolecules. Due to the presence of polymer, the solubility and stability of CM and CP increased significantly in aqueous media. Since the new macromolecules were including the hydrophilic polymeric and curcumin hydrophobic units, they self-assembled into spherical nanostructures, which were characterized by Field emission scanning electron microscopy (FE-SEM) and transmission electron microscopy (TEM) images. The synthetic nanostructures exhibited a controlled release of curcumin unit in the acidic environment. In vitro experiments showed that the new macromolecules are potent antibacterial and antioxidant agents.

Hybrid Bionanocomposite Containing Magnesium Hydroxide Nanoparticles Embedded in a Carboxymethyl Cellulose Hydrogel Plus Silk Fibroin as a Scaffold for Wound Dressing Applications

Based on the promising biomedical developments in wound healing strategies, herein, a new nanobiocomposite scaffold was designed and presented by incorporation of carboxymethyl cellulose hydrogels prepared using epichlorohydrin as a cross-linking agent (CMC hydrogel), a natural silk fibroin (SF) protein, and magnesium hydroxide nanoparticles (Mg(OH)2 NPs). Biological evaluation of the CMC hydrogel/SF/Mg(OH)2 nanobiocomposite scaffold was conducted via in vitro cell viability assays and in vivo assays, red blood cell hemolysis, and antibiofilm assays. Considering the cell viability percentage of Hu02 cells (84.5%) in the presence of the prepared nanobiocomposite after 7 days, it was indicated that this new nanoscaffold was biocompatible. The signs of excellent hemocompatibility and the high antibacterial activity were observed due to the low-point hemolytic effect (8.3%) and high-level potential in constraining the P. aeruginosa biofilm formation with a low OD value (0.13). Moreover, in vivo wound healing assay results indicated that the wound healing method was faster in mice treated with the prepared nanobiocomposite scaffold (82.29%) than the control group (75.63%) in 12 days. Apart from the structural characterization of the CMC hydrogel/SF/Mg(OH)2 nanobiocomposite through FTIR, EDX, FESEM, and TG analyses, compressive mechanical tests, contact angle, porosity, and swelling ratio studies indicated that the combination of the CMC hydrogel structure with SF protein and Mg(OH)2 NPs could significantly impact Young's modulus (from 11.34 to 10.14 MPa), tensile strength (from 299.35 to 250.78 MPa), elongation at break (12.52 to 12.84%), hydrophilicity, and water uptake capacity (92.5%).

Nanocomplexes of curcumin and glycated bovine serum albumin: The formation mechanism and effect of glycation on their physicochemical properties

Bovine serum albumin (BSA) and BSA-glucose conjugates (GBSAⅠ and GBSAⅠI) with different extent of glycation were complexed with curcumin (CUR). The formation mechanism of BSA/GBSA-CUR complexes and the effect of glycation on their physicochemical properties were investigated. Fluorescence quenching and FTIR analysis indicated that the BSA/GBSA-CUR nanocomplexes were formed mainly by hydrophobic interactions. XRD analysis demonstrated that CUR was present in an amorphous state in the nanocomplexes. BSA with a greater extent of glycation (BSA < GBSAⅠ<GBSAⅠI) displayed a higher binding affinity for CUR. The highest CUR encapsulation efficiency (86.77%) and loading capacity (7.81 mg/g) were obtained in the GBSAⅠI-CUR nanocomplex. The zeta-potential varied from -17.45 to -27.65 mV, depending on the extent of glycation. Furthermore, the physicochemical stability of BSA/GBSA-CUR nanocomplexes increased with the increasing extent of glycation of BSA. Thus, the obtained GBSAⅠI have the potential to become new delivery carriers for encapsulating hydrophobic food components.

Aminocellulose-Grafted Polymeric Nanoparticles for Selective Targeting of CHEK2-Deficient Colorectal Cancer

We report the formulation of aminocellulose-grafted polymeric nanoparticles containing LCS-1 for synthetic lethal targeting of checkpoint kinase 2 (CHEK2)-deficient HCT116 colon cancer (CRC) cells to surpass the limitations associated with the solubility of LCS-1 (a superoxide dismutase inhibitor). Aminocellulose (AC), a highly biocompatible and biodegradable hydrophilic polymer, was grafted over polycaprolactone (PCL), and a nanoprecipitation method was employed for formulating nanoparticles containing LCS-1. In this study, we exploited the synthetic lethal interaction between SOD1 and CHEK2 for the specific inhibition of CHEK2-deficient HCT116 CRC cells using LCS-1-loaded PCL-AC NPs. Furthermore, the effects of formation of protein corona on PCL-AC nanoparticles were also assessed in terms of size, cellular uptake, and cell viability. LCS-1-loaded NPs were evaluated for their size, zeta potential, and polydispersity index using a zetasizer, and their morphological characteristics were assessed by transmission electron microscopy, scanning electron microscopy, and atomic force microscopy analyses. Cellular internalization using confocal microscopy exhibited that nanoparticles were uptaken by HCT116 cells. Also, nanoparticles were cytocompatible as they did not induce cytotoxicity in hTERT and HEK-293 cells. The LCS-1-loaded PCL-AC NPs were quite hemocompatible and were 240 times more selective in killing CHEK2-deficient cells as compared to CHEK2-proficient CRC cells. Moreover, PCL-AC NPs exhibited that the protein corona-coated nanoparticles were incubated in the human and fetal bovine sera as visualized by SDS-PAGE. A slight increment in hydrodynamic diameter was observed for corona-coated PCL-AC nanoparticles, and size increment was further confirmed by TEM. Corona-coated PCL-AC NPs also exhibited cellular uptake as demonstrated by flow cytometric analysis and did not cause cytotoxic effects on hTERT cells. The nanoformulation was developed to enhance therapeutic potential of the drug LCS-1 for enhanced lethality of colorectal cancer cells with CHEK2 deficiency.

Photoinduced Antimicrobial Activity of Curcumin-Containing Coatings: Molecular Interaction, Stability and Potential Application in Food Decontamination

Polyvinyl acetate (PVAc) and curcumin (Cu) were utilized for preparing new protecting PVAc-Cu x (x = 1, 5 and 10) coatings exerting antimicrobial photodynamic activity upon white light irradiation. Toward Salmonella typhimurium or Staphylococcus aureus, the killing efficiency represented the dependence on the Cu concentration and irradiation intensity. Toward S. aureus, the killing efficiency of PVAc-Cu 10 coating reached 93% at an energy density of 72 J/cm2. With the change in storage time of coating, the results implied significant stability of photosterilization efficiency within 60 days. Compared with the control experiment, lower total viable counts (TVCs) and total volatile basic nitrogen (TVB-N) values in fresh meat packaged by PVDC films with PVAc-Cu 10 coatings during storage at 4 °C demonstrated the practicability of the PVAc-Cu x coatings in decontaminating fresh pork. PVAc packed curcumin tightly within polymer chains, thus preventing tautomerization or, more probably, conformational transition, which is advantageous for improving photostability and emission lifetime.

Silk Nanoparticles: A Natural Polymeric Platform for Nitric Oxide Delivery in Biomedical Applications

In this study, the preparation and characterization of nitric oxide (NO) releasing silk fibroin nanoparticles (SF NPs) are described for the first time. S-Nitroso-N-acetylpenicillamine (SNAP)-loaded SF NPs (SNAP-SF NPs) were prepared via an antisolvent/self-assembling method by adding a SNAP/ethanol solution to an aqueous SF solution and freeze-thawing. The prepared SNAP-SF NPs had a diameter ranging from 300 to 400 nm and an overall negative charge of -28.76 ± 0.73 mV. Among the different SNAP/SF ratios tested, the highest encapsulation efficiency (18.3 ± 1.3%) and loading capacity (9.1 ± 0.6%) values were attributed to the 1:1 ratio. The deconvolution of the amide I band in the FTIR spectra of SF NPs and SNAP-SF NPs showed an increase in the β-sheet content for SNAP-SF NPs, confirming the hydrophobic interactions between SNAP and silk macromolecules. SNAP-SF NPs released up to 1.31 ± 0.02 × 10^-10 mol min^-1 mg^-1 NO over a 24 h period. Moreover, SNAP-SF NPs showed concentration-dependent antibacterial effects against methicillin-resistant Staphylococcus aureus and Escherichia coli. Furthermore, they did not elicit any marked cytotoxicity against 3T3 mouse fibroblast cells at concentrations equal to or below 2 mg/mL. Overall, these results demonstrated that SNAP-SF NPs have great potential to be used as a NO delivery platform for biomedical applications such as tissue engineering and wound healing, where synergistic properties of SF and NO are desired.

Fibroin nanoparticles: a promising drug delivery system

Fibroin is a dominant silk protein that possesses ideal properties as a biomaterial for drug delivery. Recently, the development of fibroin nanoparticles (FNPs) for various biomedical applications has been extensively studied. Due to their versatility and chemical modifiability, FNPs can encapsulate different types of therapeutic compounds, including small and big molecules, proteins, enzymes, vaccines, and genetic materials. Moreover, FNPs are able to be administered both parenterally and non-parenterally. This review summaries basic information on the silk and fibroin origin and characteristics, followed by the up-to-date data on the FNPs preparation and characterization methods. In addition, their medical applications as a drug delivery system are in-depth explored based on several administrative routes of parenteral, oral, transdermal, ocular, orthopedic, and respiratory. Finally, the challenges and suggested solutions, as well as the future outlooks of these systems are discussed.

Direct Quantification of Drug Loading Content in Polymeric Nanoparticles by Infrared Spectroscopy

Nanotechnology has enabled the development of novel therapeutic strategies such as targeted nanodrug delivery systems, control and stimulus-responsive release mechanisms, and the production of theranostic agents. As a prerequisite for the use of nanoparticles as drug delivery systems, the amount of loaded drug must be precisely quantified, a task for which two approaches are currently used. However, both approaches suffer from the inefficiencies of drug extraction and of the solid-liquid separation process, as well as from dilution errors. This work describes a new, reliable, and simple method for direct drug quantification in polymeric nanoparticles using attenuated total reflection Fourier transform infrared spectroscopy, which can be adapted for a wide variety of drug delivery systems. Silk fibroin nanoparticles and naringenin were used as model polymeric nanoparticle carrier and drug, respectively. The specificity, linearity, detection limit, precision, and accuracy of the spectroscopic approach were determined in order to validate the method. A good linear relation was observed within 0.00 to 7.89% of naringenin relative mass with an R2 of 0.973. The accuracy was determined by the spike and recovery method. The results showed an average 104% recovery. The limit of detection and limit of quantification of the drug loading content were determined to be 0.3 and 1.0%, respectively. The method's robustness is demonstrated by the notable similarities between the calibrations carried out using two different equipment setups at two different institutions.

Tuning Microcapsule Shell Thickness and Structure with Silk Fibroin and Nanoparticles for Sustained Release

Microcapsules have attracted widespread interest for their unique properties in encapsulation, protection, and separation of active ingredients from the surrounding environment. However, microcapsule carriers with controllable shell thickness, permeability, good mechanical properties, and thermostability are challenging to obtain. Herein, robust and versatile composite microcapsules were fabricated using SiO₂ nanoparticle-stabilized (Pickering) oil emulsions as core templates, while silk fibroin (SF) was assembled at the oil/water interface. This process resulted in the formation of physically and chemically stable microcapsules with a thick (∼800 nm) shell that protected the encapsulated ingredient from high shear forces and high temperatures during spray-drying. SiO₂ nanoparticles were randomly distributed in the shell matrix after preparation, making the microcapsules mechanically robust (4.48 times higher than control samples prepared using surfactant Tween 80 instead of the SiO₂ nanoparticles), as well as thermostable (retained shape to 900 °C). The microcapsules displayed tunable drug release by adjusting the SF content in the shell. Under optimal conditions (weight ratio of SiO₂/SF = 7:10, corn oil content about 55 wt %), a model drug (curcumin) was encapsulated in the SF microcapsules with an encapsulation efficiency up to 95%. The in vitro drug release from these SF microcapsules lasted longer than control microcapsules, demonstrating the capability of these novel microcapsules in sustaining drug release.

Multifunctional Bio-Nanocomposite Coatings for Perishable Fruits

Hunger and chronic undernourishment impact over 800 million people, which translates to ≈10.7% of the world's population. While countries are increasingly making efforts to reduce poverty and hunger by pursuing sustainable energy and agricultural practices, a third of the food produced around the globe still is wasted and never consumed. Reducing food shortages is vital in this effort and is often addressed by the development of genetically modified produce or chemical additives and inedible coatings, which create additional health and environmental concerns. Herein, a multifunctional bio-nanocomposite comprised largely of egg-derived polymers and cellulose nanomaterials as a conformal coating onto fresh produce that slows down food decay by retarding ripening, dehydration, and microbial invasion is reported. The coating is edible, washable, and made from readily available inexpensive or waste materials, which makes it a promising economic alternative to commercially available fruit coatings and a solution to combat food wastage that is rampant in the world.

Gellable silk fibroin-polyethylene sponge for hemostasis

Traditional haemostatic materials generally have slow hemostasis rate and poor biocompatibility. This paper reports on the haemostatic properties and mechanism of silk fibroin (SF). SF-PEG sponge that could be solubilised and changed to gel form by blood was fabricated through mixing SF and polyethylene glycol (PEG, 1500 Da) followed by lyophilisation of the mixed solution. SF-PEG sponge, together with control samples of SF sponge (no PEG) and a commercially available haemostatic material, gelatine sponge, were subjected to the hemostasis tests using a liver trauma model of rabbit. The results showed that SF was superior to gelatine sponge in hemostasis time (136.17 ± 62.27 s and 249.83 ± 29.18 s) and blood loss (2.16 ± 1.27 g vs. 4.97 ± 1.44 g). Furthermore, in vitro experiments indicated SF-PEG sol-gel transition promoted platelet adhesion and aggregation, as well as platelet-fibrinogen interaction. Therefore, except for the physical blocking of bleeding port due to PEG-induced SF fast gelation, SF might also have an impact on blood coagulation process, a phenomenon that has not been reported before. In conclusion, SF is a new type of haemostatic material that might be able to meet the requirements of speed, efficiency and biosafety in a variety of clinical applications.

Crosslinked Fibroin Nanoparticles: Investigations on Biostability, Cytotoxicity, and Cellular Internalization

Recently, crosslinked fibroin nanoparticles (FNP) using the crosslinker 1-ethyl-3-(3-dimethylaminopropyl) carbodiimide hydrochloride (EDC) or the polymer poly(ethylenimine) (PEI) have been developed and showed potentials as novel drug delivery systems. Thus, this study further investigated the biological properties of these crosslinked FNP by labeling them with fluorescein isothiocyanate (FITC) for in vitro studies. All formulations possessed a mean particle size of approximately 300 nm and a tunable zeta potential (-20 to + 30 mV) dependent on the amount/type of crosslinkers. The FITC-bound FNP showed no significant difference in physical properties compared to the blank FNP. They possessed a binding efficacy of 3.3% w/w, and no FITC was released in sink condition up to 8 h. All formulations were colloidal stable in the sheep whole blood. The degradation rate of these FNP in blood could be controlled depending on their crosslink degree. Moreover, no potential toxicity in erythrocytes, Caco-2, HepG2, and 9L cells was noted for all formulations at particle concentrations of < 1 mg/mL. Finally, all FNP were internalized into the Caco-2 cells after 3 h incubation. The uptake rate of the positively charged particles was significantly higher than the negatively charged ones. In summary, the crosslinked FNP were safe and showed high potentials as versatile systems for biomedical applications.

Curcumin Delivery Mediated by Bio-Based Nanoparticles: A Review

Todays, nano-pharmaceutics is emerging as an important field of science to develop and improve efficacy of different drugs. Although nutraceuticals are currently being utilized in the prevention and treatment of various chronic diseases such as cancers, a number of them have displayed issues associated with their solubility, bioavailability, and bio-degradability. In the present review, we focus on curcumin, an important and widely used polyphenol, with diverse pharmacological activities such as anti-inflammatory, anti-carcinogenic, anti-viral, etc. Notwithstanding, it also exhibits poor solubility and bioavailability that may compromise its clinical application to a great extent. Therefore, the manipulation and encapsulation of curcumin into a nanocarrier formulation can overcome these major drawbacks and potentially may lead to a far superior therapeutic efficacy. Among different types of nanocarriers, biological and biopolymer carriers have attracted a significant attention due to their pleiotropic features. Thus, in the present review, the potential protective and therapeutic applications of curcumin, as well as different types of bio-nanocarriers, which can be used to deliver curcumin effectively to the different target sites will be discussed.

Transgenic PDGF-BB/sericin hydrogel supports for cell proliferation and osteogenic differentiation

The present study demonstrates fabrication of PDGF-BB functionalized sericin hydrogel to explore biomaterials-related utility in bone tissue engineering.

Crystal-Seeded Growth of pH-Responsive Metal-Organic Frameworks for Enhancing Encapsulation, Stability, and Bioactivity of Hydrophobicity Compounds

Zeolitic imidazolate framework-L (ZIF-L) could effectively improve the stability, controlled release, and anticancer activity of natural hydrophobicity drugs in drug delivery systems (DDSs). A simple and universal strategy was developed to prepare the curcumin-loaded ZIF-L (CCM@ZIF-L) by the antisolvent coprecipitation method, which was different from the traditional approaches. The microcrystal molecules of curcumin were used as the core of ZIF-L growth to form CCM@ZIF-L, which has a very high drug encapsulation efficiency of 98.21% and a regular leaf or cruciate flower-like structure. The formation of CCM@ZIF-L with a distinct composite structure was supported by scanning electron microscopy, transmission electron microscopy, Fourier-transform infrared, powder X-ray diffraction, and zeta-potential. Because of the protective effect of ZIF-L, CCM@ZIF-L exhibited excellent stability and about a 5-fold increase in temperature stability over free curcumin. CCM@ZIF-L exhibited controlled drug release behavior in simulated in vitro tumor microenvironments (almost 81.2% drug release over a period of 72 h). Furthermore, confocal laser scanning microscopy results and cytotoxicity experiments confirmed that the encapsulated curcumin showed a significant improvement in cellular uptake and anticancer activity against A549 cancer cells. Moreover, the curcumin encapsulated in ZIF-L exhibited remarkable cellular antioxidant activity based on MGC-803 cell models. This work presents a novel approach to solve the drug loading problem by employing ZIF-L and exhibits enormous potential of ZIF-L as an effective DDS in cancer treatments.

Fabrication of Thymoquinone-Loaded Albumin Nanoparticles by Microfluidic Particle Synthesis and Their Effect on Planarian Regeneration

Thymoquinone is the main bioactive component of the plant Nigella sativa, which is commonly known as black seeds and has several therapeutic effects. However, clinical applications of thymoquinone are limited due to its hydrophobic nature. In this study, thymoquinone is encapsulated in albumin nanoparticles by using a microfluidic platform to overcome this limitation. The mean particle sizes of empty and thymoquinone-loaded nanoparticles are determined as 271.3 and 315.6 nm, respectively, with polydispersity index values both lower than 0.25. In addition to particle size distribution measurements, characterizations of the prepared nanoparticles such as zeta potential measurements, in vitro release studies, as well as scanning electron microscopy, Fourier-transform infrared, and differential scanning calorimetry analyses are also carried out. To determine the effect of thymoquinone on neural regeneration, planarians are used as the model organism. After application of free and encapsulated thymoquinone, planarians are amputated and the fragments are observed in terms of head and tail regeneration, swimming pattern, and behavior. The results indicate that thymoquinone affects their behavior and primarily enhances head regeneration of planarians. In addition, it is shown that encapsulation of thymoquinone not only enhances the thermal stability of the molecule but also decreases its toxicity.

Oral Curcumin via Hydrophobic Porous Silicon Carrier: Preparation, Characterization, and Toxicological Evaluation In Vivo

Curcumin has antioxidant, anti-inflammatory, antimicrobial, and anticarcinogenic activities. However, the clinical application of curcumin has been restricted by the poor water solubility and low bioavailability of this molecule. In this work, hydrophobic porous silicon (pSi) particles were prepared by electrochemical etching method and grafted with the different hydrophobic groups on their surfaces. The loading efficiency of curcumin in pSi has been investigated. The properties of pSi particles have been characterized by scanning electron microscopy (SEM) and Fourier transform-infrared spectroscopy (FTIR). The highest loading efficiency of curcumin can be obtained with pSi surface modified with the octadecyl silane group. The release properties of curcumin in hydrophobic pSi have been researched in vitro and in vivo. The curcumin in the hydrophobic pSi surface keeps a high antioxidant bioactivity. The toxicological evaluation of the hydrophobic pSi particles indicates they have a high in vivo biocompatibility within the observed dose ranges. The hydrophobic pSi particles could provide an effective and controlled release delivery carrier for curcumin, which may provide a new tool platform for the further development of curcumin.

Extended release formulations using silk proteins for controlled delivery of therapeutics

INTRODUCTION

Silk is a promising biomaterial for controlled delivery of therapeutics and has a unique protein chemistry that can be tuned to form different carrier formats. The protein has been studied for sustained release depot systems for the targeted or localized delivery of drugs.

AREAS COVERED

An overview of natural silk proteins for controlled delivery of therapeutics is provided, with a focus on the features of silk proteins that allow them to be useful tools for controlled delivery. Recent applications of natural silk proteins as controlled delivery systems are also summarized.

EXPERT OPINION

The versatility of silk proteins makes them desirable biomaterials for a broad range of applications for controlled delivery of both small and large molecules. Further, the degradation profile leading to peptides and amino acids provides compatibility with pH-sensitive therapeutics. While silk sericin and spider silks are under study, silk fibroin extracted from silkworms (e.g. Bombyx mori) dominates pharmaceutical studies with silk. Silk fibroin can be formed into drug delivery tools for systemic or local injections, topical and transdermal applications, and implantation; depending on the target disease and therapeutic molecule. In vitro to in vivo correlations and scale-up needs are the next steps towards clinical applications.