Improved blood compatibility of rapamycin-eluting stent by incorporating curcumin

A gene-coated microneedle patch based on industrialized ultrasonic spraying technology with a polycation vector to improve antitumor efficacy

A coated microneedle patch is a reliable way to load gene on a surface as a transdermal gene delivery platform. But there are many limitations to the traditional methods to fabricate a coated microneedle patch, such as the fact that they are time consuming or the difficulty in controlling the loading content. In this research, ultrasonic spraying technology, as an industrialized production method, was first used to fabricate a gene-coated microneedle patch. First, the p53 expression plasmid (p53 DNA) was ultrasonically sprayed on a polycaprolactone (PCL) microneedle patch (D@MNP). To promote the transfection efficiency, polycation polyethylenimine (PEI), as a vector, was then ultrasonically sprayed on D@MNP (P@D@MNP). From the experimental results, although two layers were sprayed step by step, no obvious stratification could be observed. The vector PEI interweaved with genes and inhibited the gene release profile, but it changed the released naked genes to positively charged complexes, which would promote gene transfection efficiency. In subsequent in vivo experiments, the anti-tumor efficacy of the "P@D@MNP treated group" could reach 84.7%, although it had the lowest gene release profile. In contrast, the anti-tumor efficacy of the "intravenous injection group" and "D@MNP treated group" was only 24.3% and 59.3%, respectively. Overall, P@D@MNP was a safe and efficient device to treat the subdermal tumor. Ultrasonic spraying technology provided an industrialized method to fabricate the coated microneedle patch as a transdermal gene/drug delivery platform.

Fabrication and characterization of silk fibroin coating on APTES pretreated Mg-Zn-Ca alloy

To delay the degradation of magnesium alloys, silk fibroin as a natural organic polymer coating was fabricated on a 3-amino-propyltriethoxysilane (APTES) pretreated Mg-Zn-Ca alloy. APTES pretreatment coated the surface of magnesium alloys with amino groups, which can bond with functional groups in silk fibroin to form a compact coating/substrate interface. The influences of the APTES concentration and drying temperature on the coating adhesion and interface were investigated to explore the optimal parameters in the fabrication process. The nanoporous silk fibroin films completely covered the APTES pretreated Mg-Zn-Ca surface, which reached a thickness of ~7 μm. The chemical states for the coated Mg-Zn-Ca alloy were compared to those of the bare Mg-Zn-Ca alloy and the APTES pretreated Mg-Zn-Ca alloy to illustrate the coating mechanism. During in vitro degradation and electrochemical measurements in simulated body fluid (SBF), the samples with the silk fibroin coating showed remarkably improved corrosion resistance and a slower degradation rate compared to those of the bare samples, suggesting that the silk fibroin coating was an effective protection coating for the substrates and can delay the degradation of magnesium alloys. Moreover, a model for the in vitro degradation was proposed. In vitro cell experiments confirmed the excellent biocompatibility of silk fibroin coated Mg-Zn-Ca structure.

Silk fibroin film-coated MgZnCa alloy with enhanced in vitro and in vivo performance prepared using surface activation

Magnesium and its alloys have generated considerable interest as one of the most promising biodegradable metals for biomedical bone implants. However, the enormous challenges are to improve their rapid corrosion excessively as well as to endow them with biocompatibility and biosafety. Herein, we introduce a natural silk fibroin protein coating to control the corrosion resistance and enhance the biocompatibility of MgZnCa alloy. To obtain a robust and reliable coated structure, different surface-activation processes are employed to increase the available functional groups on MgZnCa surfaces before coating. Compared to oxygen plasma activation, our unique vacuum ultraviolet-ozone (VUV/O₃) activation method is effective in realizing uniform silk fibroin films as a protective barrier on MgZnCa alloy surfaces, and the nanoscratch test verified the superior adhesion strength of the silk fibroin-coated magnesium alloy structure. Long-term immersion results combined with electrochemical tests showed the preferable in vitro anticorrosion behavior and a low degradation rate of coated Mg alloy (1/8 times that of uncoated Mg alloy). Cell adhesion and cytotoxicity tests demonstrated that silk fibroin-coated MgZnCa presented improved biocompatibility with bone marrow mesenchymal stem cells. An animal study involving silk fibroin-coated MgZnCa implanted on one side of a rabbit spine for 180 days showed remarkably improved in vivo corrosion resistance, with 1/18 times the degradation rate of uncoated MgZnCa. These results not only comprehensively confirmed the validity of the VUV/O₃-activation method as a coating strategy but also implied the tremendous potential of the modified Mg alloy for application as a degradable biomedical implant material. STATEMENT OF SIGNIFICANCE: MgZnCa alloy is a promising material in clinical implantation. Silk fibroin (SF) is a natural organic material with biocompatibility and biodegradability. To date, the combination of SF and MgZnCa alloy has exhibited considerable prospects for orthopedic applications. The realization of a direct coating is an enormous challenge because strong chemical bonds cannot be easily formed between organic and inorganic materials. To solve this bottleneck, we proposed a unique vacuum ultraviolet-ozone (VUV/O₃) surface-activation method for the first time to modify the Mg alloy surface before SF coating, which significantly enhanced both in vitro and in vivo performance, such as superior biocompatibility and remarkably improved corrosion resistance of magnesium alloys (∼1/18 the in vivo degradation rate of uncoated MgZnCa).

Combination therapy of curcumin and alendronate modulates bone turnover markers and enhances bone mineral density in postmenopausal women with osteoporosis

OBJECTIVE

This study evaluated the effects of combination therapy of curcumin and alendronate on BMD and bone turnover markers in postmenopausal women with osteoporosis.

SUBJECTS AND METHODS

In a randomized, double-blind trial study, 60 postmenopausal women were divided into three groups: control, alendronate, and alendronate + curcumin. Each group included 20 patients. Total body, total hip, lumbar spine and femoral neck BMDs were measured by dual-energy X-ray absorptiometry (DXA) at baseline and after 12 months of therapy. Bone turnover markers such as bone-specific alkaline phosphatase (BALP), osteocalcin and C-terminal cross-linking telopeptide of type I collagen (CTx) were measured at the outset and 6 months later.

RESULTS

Patients in the control group suffered a significant decrease in BMD and increased bone turnover markers at the end of study. The group treated with only alendronate showed significantly decreased levels of BALP and CTx and increased levels of osteocalcin compared to the control group. The alendronate group also showed significant increases in the total body, total hip, lumbar spine and femoral neck BMDs at the end of study compared to the control group. In the curcumin + alendronate group, BALP and CTx levels decreased and osteocalcin levels increased significantly at the end of study compared to the control and alendronate groups. BMD indexes also increased in four areas significantly at the end of study compared to the control and alendronate groups.

CONCLUSION

The combination of curcumin and alendronate has beneficial effects on BMD and bone turnover markers among postmenopausal women with osteoporosis. Arch Endocrinol Metab. 2018;62(4):438-45.

The regulatory role of curcumin on platelet functions

Curcumin, the main ingredient of Curcuma longa L., has been used as a spice and as a herbal medicine with different therapeutic characteristics for centuries in Asian countries. This phytochemical has been shown to possess beneficial antiplatelet activity that has introduced it as a promising candidate for the treatment of thromboembolism, atherothrombosis, and inflammatory diseases. Platelet dysfunction under different circumstances may lead to cardiovascular disease, and curcumin has been shown to have beneficial effects on platelet dysfunction in several studies. Therefore, this narrative review is aimed to summarize available evidence on the antiplatelet activity of curcumin and related molecular mechanisms for this activity.

Enhancement of anticancer activity and drug delivery of chitosan-curcumin nanoparticle via molecular docking and simulation analysis

Computational analyses followed by traditional wet-bench experiments have become a method of choice due to successful results. To enhance the solubility and bioavailability of curcumin within chitosan nanoparticle, we have exploited computational methodologies i.e. docking, BBD-RSM and MD simulation for the polymer selection, NPs' formulation, optimization and their stability confirmation in an aqueous medium, respectively. Formulated CSCur NPs were assessed for in-vitro release, which exhibited a sustained release pattern and four-fold higher cytotoxic activity in a nanoparticulated system. Enhanced uptake, apoptotic effect of CSCur NPs were established by morphological changes in cells as observed by fluorescence microscopy and FE-SEM. DNA damage, cell-cycle blockage and elevated ROS levels further confirm the anticancer activity of the CSCur NPs following apoptotic pathways. In-vivo study on Danio rerio, for uptake and toxicity reveal the particle's biocompatibility and nontoxicity. Therefore, CSCur NPs could be the potential formulation for a safe chemotherapeutic drug for cancer.

Killing malignant melanoma cells with protoporphyrin IX-loaded polymersome-mediated photodynamic therapy and cold atmospheric plasma

Traditional cancer treatments contain several limitations such as incomplete ablation and multidrug resistance. It is known that photodynamic therapy (PDT) is an effective treatment for several tumor types especially melanoma cells. During the PDT process, protoporphyrin IX (PpIX), an effective photosensitizer, can selectively kill cancer cells by activating a special light source. When tumor cells encapsulate a photosensitizer, they can be easily excited into an excited state by a light source. In this study, cold atmospheric plasma (CAP) was used as a novel light source. Results of some studies have showed that cancer cells can be effectively killed by using either a light source or an individual treatment due to the generation of reactive oxygen species and electrons from a wide range of wavelengths, which suggest that CAP can act as a potential light source for anticancer applications compared with UV light sources. Results of the present in vitro study indicated for the first time that PpIX can be successfully loaded into polymersomes. Most importantly, cell viability studies revealed that PpIX-loaded polymersomes had a low toxicity to healthy fibroblasts (20% were killed) at a concentration of 400 µg/mL, but they showed a great potential to selectively kill melanoma cells (almost 50% were killed). With the application of CAP posttreatment, melanoma cell viability significantly decreased (80% were killed) compared to not using a light source (45% were killed) or using a UV light source (65% were killed). In summary, these results indicated for the first time that PpIX-loaded polymersomes together with CAP posttreatment could be a promising tool for skin cancer drug delivery with selective toxicity toward melanoma cells sparing healthy fibroblasts.

Direct Adsorption of Anti-CD34 Antibodies on the Nano-Porous Stent Surface to Enhance Endothelialization

BACKGROUND

In-stent restenosis following the insertion of conventional drug-eluting stent has become an extremely serious problem due to coating techniques, with polymer matrices used to bind biological ingredients to the stent surface. However, several studies have indicated that new pro-healing technique could prevent stent thrombosis that can be caused by conventional drug-eluting stents.

METHODS

A novel method of attaching anti-CD34 antibodies directly on the porous surface of a 316L stainless steel bare metal stent was developed in this study, which achieved both high stability of attached anti-CD34 antibodies on the metal stent surface and high antibody activity for stem cell capture.

RESULTS

The in vitro and in vivo experimental results indicated that the new stent with directly coupled anti-CD34 antibodies can efficiently enhance stent endothelialization.

CONCLUSIONS

This study indicates that we have developed a unique method of attaching anti-CD34 antibodies directly on the porous surface of a 316L stainless steel bare metal stent, which provides a novel polymer-free approach for developing pro-healing stents.

Phytochemical Compounds and Protection from Cardiovascular Diseases: A State of the Art

Cardiovascular diseases represent a worldwide relevant socioeconomical problem. Cardiovascular disease prevention relies also on lifestyle changes, including dietary habits. The cardioprotective effects of several foods and dietary supplements in both animal models and in humans have been explored. It was found that beneficial effects are mainly dependent on antioxidant and anti-inflammatory properties, also involving modulation of mitochondrial function. Resveratrol is one of the most studied phytochemical compounds and it is provided with several benefits in cardiovascular diseases as well as in other pathological conditions (such as cancer). Other relevant compounds are Brassica oleracea, curcumin, and berberine, and they all exert beneficial effects in several diseases. In the attempt to provide a comprehensive reference tool for both researchers and clinicians, we summarized in the present paper the existing literature on both preclinical and clinical cardioprotective effects of each mentioned phytochemical. We structured the discussion of each compound by analyzing, first, its cellular molecular targets of action, subsequently focusing on results from applications in both ex vivo and in vivo models, finally discussing the relevance of the compound in the context of human diseases.

Recent developments in curcumin and curcumin based polymeric materials for biomedical applications: A review

Turmeric (Curcuma longa) is a popular Indian spice that has been used for centuries in herbal medicines for the treatment of a variety of ailments such as rheumatism, diabetic ulcers, anorexia, cough and sinusitis. Curcumin (diferuloylmethane) is the main curcuminoid present in turmeric and responsible for its yellow color. Curcumin has been shown to possess significant anti-inflammatory, anti-oxidant, anti-carcinogenic, anti-mutagenic, anticoagulant and anti-infective effects. This review summarizes and discusses recently published papers on the key biomedical applications of curcumin based materials. The highlighted studies in the review provide evidence of the ability of curcumin to show the significant vitro antioxidant, diabetic complication, antimicrobial, neuroprotective, anti-cancer activities and detection of hypochlorous acid, wound healing, treatment of major depression, healing of paracentesis, and treatment of carcinoma and optical detection of pyrrole properties. Hydrophobic nature of this polyphenolic compound along with its rapid metabolism, physicochemical and biological instability contribute to its poor bioavailability. To redress these problems several approaches have been proposed like encapsulation of curcumin in liposomes and polymeric micelles, inclusion complex formation with cyclodextrin, formation of polymer-curcumin conjugates, etc.

Study of drug-eluting coating on metal coronary stent

Drug-eluting stent has been proved to decrease the restenosis caused by the stent implantation, owing to the existence of a drug-eluting coating on the stent. For ensuring the effectivity and security of the drug-eluting stent during the service period, the uniform surface, good deformation and stabilized drug release behavior of the stents should be satisfied. In this study, the performances mentioned were studied on stainless steel stents. The results showed that the surface morphology of the coating was affected by the sorts of solvent, the parameters of the spraying process and the addition of the plasticizer. The drug-eluting profile of the coating was influenced by the plasticizer content and PLGA/drug ratio of the coating. Meanwhile, the plasticizer as an additional agent obviously increased the deformation performance of the coating. Optimized parameters for preparation of the drug-eluting coating were investigated to obtain a drug-eluting coating with good integrated performances.

Curcumin Protects against Ovariectomy-Induced Bone Changes in Rat Model

Osteoporosis is a metabolic disease affecting both men and women especially in postmenopausal women. Curcumin possesses many medicinal properties. In this study, thirty two female Sprague-Dawley rats were used to determine the potential effect of curcumin in prevention of bone loss following ovariectomy. The animals were divided into Sham group, ovariectomised control, ovariectomised treated with curcumin 110 mg/kg and ovariectomised treated with Premarin 100 μg/kg. The treatments were given via daily oral gavages for 60 days. The structural parameters such as bone volume, trabecular number, trabecular thickness and trabecular separation were found to be deteriorated in ovariectomised rats compared to Sham group. Moreover, the reduced osteoblast count, the increased osteoclast count and increased eroded surface were found in ovariectomised groups. Treatment with curcumin was able to reverse all these ovariectomy-induced deteriorations. Curcumin treatment was as effective as Premarin in most parameters except the bone volume and eroded surface, which were better than Premarin. The high dose of curcumin treatment was not only able to reduce the osteoclast number but also increase the osteoblast count. Therefore, the potential effect of curcumin can be applied as an alternative to oestrogen for prevention of postmenopausal osteoporosis.

The effect of curcumin in the ectonucleotidases and acetylcholinesterase activities in synaptosomes from the cerebral cortex of cigarette smoke-exposed rats

With the evidence that curcumin may be a potent neuroprotective agent and that cigarette smoke is associated with a decline in the cognitive performance as our bases, we investigated the activities of Ecto-Nucleoside Triphosphate Diphosphohydrolase (NTPDase), 5'-nucleotidase and acetylcholinesterase (AChE) in cerebral cortex synaptosomes from cigarette smoke-exposed rats treated with curcumin (Cur). The experimental procedures entailed two sets of experiments. In the first set, the groups were vehicle, Cur 12·5, 25 and 50 mg·kg(-1) ; those in the second set were vehicle, smoke, smoke and Cur 12·5, 25 and 50 mg·kg(-1) . Curcumin prevented the increased NTPDase, 5'-nucleotidase and AChE activities caused by smoke exposure. We suggest that treatment with Cur was protective because the decrease of ATP and acetylcholine (ACh) concentrations is responsible for cognitive impairment, and both ATP and ACh have key roles in neurotransmission.

The in vitro stability and in vivo pharmacokinetics of curcumin prepared as an aqueous nanoparticulate formulation

Curcumin, the natural anticancer drug and its optimum potential is limited due to lack of solubility in aqueous solvent, degradation at alkaline pH and poor tissue absorption. In order to enhance its potency and improve bioavailability, we have synthesized curcumin loaded nanoparticulate delivery system. Unlike free curcumin, it is readily dispersed in aqueous medium, showing narrow size distribution 192 nm ranges (as observed by microscope) with biocompatibility (confocal studies and TNF-alpha assay). Furthermore, it displayed enhanced stability in phosphate buffer saline by protecting encapsulated curcumin against hydrolysis and biotransformation. Most importantly, nanoparticulate curcumin was comparatively more effective than native curcumin against different cancer cell lines under in vitro condition with time due to enhanced cellular uptake resulting in reduction of cell viability by inducing apoptosis. Molecular basis of apoptosis studied by western blotting revealed blockade of nuclear factor kappa B (NFkappaB) and its regulated gene expression through inhibition of IkappaB kinase and Akt activation. In mice, nanoparticulate curcumin was more bioavailable and had a longer half-life than native curcumin as revealed from pharmacokinetics study. Thus, the results demonstrated nanoparticulate curcumin may be useful as a potential anticancer drug for treatment of various malignant tumors.

Release of PLGA-encapsulated dexamethasone from microsphere loaded porous surfaces

The aim of the present study was to investigate the morphology and function of a drug eluting metallic porous surface produced by the immobilization of poly lactide-co-glycolide microspheres bearing dexamethasone onto plasma electrolytically oxidized Ti-6Al-7Nb medical alloy. Spheres of 20 microm diameter were produced by an oil-in-water emulsion/solvent evaporation method and thermally immobilized onto titanium discs. The scanning electron microscopy investigations revealed that the size distribution and morphology of the attached spheres had not changed significantly. The drug release profiles following degradation in phosphate buffered saline for 1000 h showed that, upon immobilisation, the spheres maintained a sustained release, with a triphasic profile similar to the non-attached system. The only significant change was an increased release rate during the first 100 h. This difference was attributed to the effect of thermal attachment of the spheres to the surface.

Preparation and in vitro release profiles of drug-eluting controlled biodegradable polymer coating stents

In the present study, the different drug-eluting controlled biodegradable polymer coatings were fabricated on stainless steel stents. The coatings were not only uniform and smooth but also had excellent mechanical property. The drug release profiles of drug-eluting stents were studied in detail in this study. Depending on the drug type, different drug-eluting stents exhibited different drug release profile. There were two basic release profiles for different drug-eluting stents, i.e., two-phase release profile with burst release or linear release profile without burst release. Incorporating heparin in the rapamycin or curcumin eluting stents can improve the average drug release rate of both and the burst release of rapamycin. The average drug release rate increased with the increase of drug loading but was not proportional to increase of the ratio of drug/polymer. Fabricating the control release layer on rapamycin-eluting stent surface can prevent the burst release of rapamycin and prolong the release period of rapamycin. All results showed that the drug release profile of drug-eluting stents depends on many parameters including drug type, ratio of drug/polymer, and drug carrier properties.

Novel thrombo-resistant coating based on iron-polysaccharide complex multilayers

The biocompatibility of iron-polysaccharide complexes has been well-documented. Herein, a stable thrombo-resistant coating was fabricated by consecutive adsorption of Fe (III) and polysaccharides including heparin (Hep) and dextran sulfate (DS) onto various surface by layer-by-layer self-assembly technique via both electrostatic interaction and chemical complexation process. The absorbance at 350 nm increased linearly with the number of Fe3+/Hep multilayer, indicating the formation of multilayer structure and the uniform coating. Compared with (Fe3+/Hep)10, the (Fe3+/DS/Fe3+/Hep)5 coating was more hydrophilic and stable due to the incorporation of DS. The activated partial thromboplastin time (APTT) and platelet adhesion assays showed that both (Fe3+/Hep)10 and (Fe3+/DS/Fe3+/Hep)5 coated surfaces were anticoagulant. The complexing with ferric ions did not compromise the catalytic capacity of heparin to promote antithrombin(III)-mediated thrombin inactivation. Chromogenic assays for heparin activity proved definitively that the inhibition of locally produced thrombin was contributed to the thromboresistance of the surface-bound heparin. The surface with Hep or DS as the outmost layer showed stronger anticoagulant activity than Fe3+, indicating that the outermost layer of the coating played a key role in anticoagulant activity. The utilization of dextran sulfate/heparin surfaces was more advantageous than merely the heparin surface for improving blood-contacting medical devices for long-term usage.

Potential therapeutic effects of curcumin, the anti-inflammatory agent, against neurodegenerative, cardiovascular, pulmonary, metabolic, autoimmune and neoplastic diseases

Although safe in most cases, ancient treatments are ignored because neither their active component nor their molecular targets are well defined. This is not the case, however, with curcumin, a yellow-pigment substance and component of turmeric (Curcuma longa), which was identified more than a century ago. For centuries it has been known that turmeric exhibits anti-inflammatory activity, but extensive research performed within the past two decades has shown that this activity of turmeric is due to curcumin (diferuloylmethane). This agent has been shown to regulate numerous transcription factors, cytokines, protein kinases, adhesion molecules, redox status and enzymes that have been linked to inflammation. The process of inflammation has been shown to play a major role in most chronic illnesses, including neurodegenerative, cardiovascular, pulmonary, metabolic, autoimmune and neoplastic diseases. In the current review, we provide evidence for the potential role of curcumin in the prevention and treatment of various proinflammatory chronic diseases. These features, combined with the pharmacological safety and negligible cost, render curcumin an attractive agent to explore further.