Synthesis and characterization of cationic polymeric nanoparticles as simvastatin carriers for enhancing the osteogenesis of bone marrow mesenchymal stem cells

Development of phytotherapeutic nanoformulation containing Gypsophila eriocalyx and its evaluation as a candidate formulation for osteoporosis treatment on human bone marrow stem cells

INTRODUCTION

Osteoporosis, one of the common bone diseases, manifests itself as a decrease in bone mass. Recently, the use of medicinal plants in the search for effective and low-toxicity therapeutics for the prevention or treatment of osteoporosis has become a trending topic.

OBJECTIVE

In this study, we aim to prepare a controlled drug carrier system loaded with Gypsophila eriocalyx to determine its potential for anti-osteoporosis applications.

METHODS

Gypsophila eriocalyx extract (GEE) was prepared, and components were determined. The molecular interactions of the components with Cathepsin K (CatK), which is used as a target in drug development against osteoporosis, were revealed by in silico molecular docking and MD methods. ADMET profiles were also examined. GEE-loaded chitosan nanoparticles (CNPs) were synthesized. The nanoparticles' morphology, encapsulation efficiency, loading capacity, release profile, average size, polydispersity index, and zeta potentials were determined. The cytotoxic effects of GEE and GEE-loaded CNPs on the L929 and osteogenic proliferation profiles on human bone marrow stem cells (hBMC) were examined.

RESULTS

The MD analysis revealed no breaks or atomic changes in the dynamic system, and the docking analysis confirmed the continued interaction of identical residues. It was determined that the GEE-loaded CNP formulation was produced successfully, had no toxic effect on the L929, and had an osteogenic proliferation effect on hBMC.

CONCLUSION

In line with the in vitro and in silico results obtained, it was evaluated that GEE-loaded CNPs can be used as a controlled drug release system as a candidate formulation with phytotherapeutic properties for osteoporosis treatment.q1.

Carboxymethyl cellulose/sodium alginate hydrogel with anti-inflammatory capabilities for accelerated wound healing; In vitro and in vivo study

Recently, managing the chronic skin wounds has become increasingly challenging for healthcare professionals due to the intricate orchestration of cellular and molecular processes involved that lead to the uncontrollable inflammatory reactions which hinder the healing process. Therefore, different types of wound dressings with immunomodulatory properties have been developed in recent years to effectively regulate the immune responses, enhance angiogenesis, promote re-epithelialization, and accelerate the wound healing process. This study aims to develop a new type of immunomodulatory wound dressing utilizing carboxymethyl cellulose (CMC)/sodium alginate (Alg)-simvastatin (SIM) to simultaneously enhance the inflammatory responses and the wound healing ratio. The CMC/Alg-SIM hydrogels exhibited appropriate swelling ratio, water vapor transmission rate, and desirable degradation rate, depending on the SIM content. The fabricated dressing showed sustained release of SIM (during 5 days) that improved the proliferation of skin cells. According to the in vitro findings, the CMC/Alg-SIM hydrogel exhibited controlled pro-inflammatory responses (decreased 2.5- and 1.6-times IL-6 and TNF-α, respectively) and improved secretion of anti-inflammatory cytokines (increased 1.5- and 1.3-times IL-10 and TGF-β, respectively) in comparison with CMC/Alg. Furthermore, the CMC/Alg-SIM hydrogel facilitated rapid wound healing in the rat model with a full-thickness skin defect. After 14 days post-surgery, the wound healing ratio in the CMC/Alg hydrogel group (∼93%) was significantly greater than the control group (∼58%). Therefore, the engineered CMC/Alg-SIM hydrogel with desired immunomodulatory properties possesses the potential to enhance and accelerate skin regeneration for the management of chronic wound healing.

Statins-Their Role in Bone Tissue Metabolism and Local Applications with Different Carriers

Statins, widely prescribed for lipid disorders, primarily target 3-hydroxy-3-methylglutaryl-coenzyme A (HMG-CoA) reductase competitively and reversibly, resulting in reduced low-density lipoprotein cholesterol (LDL-C). This mechanism proves effective in lowering the risk of lipid-related diseases such as ischemic cerebrovascular and coronary artery diseases. Beyond their established use, statins are under scrutiny for potential applications in treating bone diseases. The focus of research centers mainly on simvastatin, a lipophilic statin demonstrating efficacy in preventing osteoporosis and aiding in fracture and bone defect healing. Notably, these effects manifest at elevated doses (20 mg/kg/day) of statins, posing challenges for systematic administration due to their limited bone affinity. Current investigations explore intraosseous statin delivery facilitated by specialized carriers. This paper outlines various carrier types, characterizing their structures and underscoring various statins' potential as local treatments for bone diseases.

Targeted delivery methods for RNA interference are necessary to obtain a potential functional cure for HIV/AIDS

Ribonucleic acid (RNA) is of great interest in many different therapeutic areas including infectious diseases such as immunodeficiency virus/acquired immunodeficiency syndrome (HIV/AIDS). Thanks to current, advanced treatments for HIV, the diagnosis is no longer a death sentence. However, even with these treatments, latency is suggested to persist in T-lymphocyte-rich tissues including gut-associated lymphatic tissue (GALT), spleen, and bone marrow making HIV an incurable disease. Therefore, it is important to design systems that can effectively deliver therapeutics to these tissues to fight latent infection and find a functional cure. Numerous therapeutics ranging from small molecules to cell therapies have been explored as a cure for HIV but have failed to maintain therapeutic longevity. RNA interference (RNAi) provides a unique opportunity to achieve a functional cure for those who suffer from chronic HIV/AIDS by suppressing replication of the virus. However, RNA has certain imitations in delivery as it cannot be delivered without a carrier due to its negative charge and degradation from endogenous nucleases. Here, we provide a detailed analysis of explored systems for siRNA delivery for HIV/AIDS in the context of RNA therapeutic design and nanoparticle design. In addition, we suggest strategies that should be used to target specific tissues that are rich in lymphatic tissue.

Bone-Targeting Nanoparticles of a Dendritic (Aspartic acid)3-Functionalized PEG-PLGA Biopolymer Encapsulating Simvastatin for the Treatment of Osteoporosis in Rat Models

Simvastatin (SIM) is a lipid-lowering drug that also promotes bone formation, but its high liver specificity may cause muscle damage, and the low solubility of lipophilic drugs limits the systemic administration of SIM, especially in osteoporosis (OP) studies. In this study, we utilized the bone-targeting moiety of dendritic oligopeptides consisting of three aspartic acid moieties (dAsp3) and amphiphilic polymers (poly(ethylene glycol)-block-poly(lactic-co-glycolic acid); PEG-PLGA) to create dAsp3-PEG-PLGA (APP) nanoparticles (NPs), which can carry SIM to treat OP. An in vivo imaging system showed that gold nanocluster (GNC)-PLGA/APP NPs had a significantly higher accumulation rate in representative bone tissues. In vivo experiments comparing low-dose SIM treatment (0.25 mg/kg per time, 2 times per week) showed that bone-targeting SIM/APP NPs could increase the bone formation effect compared with non-bone-targeting SIM/PP NPs in a local bone loss of hindlimb suspension (disuse) model, but did not demonstrate good bone formation in a postmenopausal (ovariectomized) model of systemic bone loss. The APP NPs could effectively target high mineral levels in bone tissue and were expected to reduce side effects in other organs affected by SIM. However, in vivo OP model testing showed that the same lower dose could not be used to treat different types of OP.

New paradigm in combination therapy of siRNA with chemotherapeutic drugs for effective cancer therapy

Chemotherapeutics drugs play a pivotal role in the treatment of cancer. However, many issues generate by chemotherapy drugs, including unfavorable harm to healthy cells and multidrug resistance (MDR), persist and have a negative impact on therapeutic outcomes. When compared to monotherapy, combination cancer therapy has many advantages, like improving efficacy through synergistic effects and overcoming drug resistance. Combination treatment may comprise several chemotherapeutics drugs and combinations of chemotherapeutic drugs with some other therapeutic options such as surgery or radiation. Cancer treatment that utilizes co-delivery strategies with siRNA and chemotherapeutic drugs has been shown to have highly effective antitumor effects in the treatment of many cancers. However, the highly complex mechanisms of chemotherapeutic drugs-siRNA pairs during the co-delivery process have received little attention. The ideal combination of chemotherapeutic drugs with siRNA is very crucial for producing the desirable anticancer effects that would greatly enhance therapeutic efficiency. This review puts an emphasis on the logic for choosing suitable chemotherapeutic drug-siRNA combinations, which may open the way for the co-delivery of chemotherapeutic drugs and siRNA for treating cancer in the clinic. This review summarizes recent breakthrough in the area of diverse mechanism-based chemotherapeutic drugs-siRNA combinations in cancer treatment.

A simvastatin-releasing scaffold with periodontal ligament stem cell sheets for periodontal regeneration

Simvastatin (SIM) has been documented to induce the osteogenic differentiation of periodontal ligament stem cells (PDLSCs). To establish an efficient release system for periodontal regeneration, a polycaprolactone (PCL) membrane scaffold containing SIM was electrospun and evaluated. The obtained PCL-SIM membrane scaffold showed sustained release up to 28 days, without deleterious effect on proliferation of PDLSCs on the scaffolds. PDLSCs were seeded onto scaffolds and their osteogenic differentiation was evaluated. After 21 days, expressions of collagen type I, alkaline phosphatase and bone sialoprotein genes were significantly upregulated and mineralized matrix formation was increased on the PCL-SIM scaffolds compared with the PCL scaffolds. In a heterotopic periodontal regeneration model, a cell sheet-scaffold construct was assembled by placement of multilayers of PDLSC sheets on PCL or PCL-SIM scaffolds, and these were then placed between dentin and ceramic bovine bone for subcutaneous implantation in athymic mice. After 8 weeks, the PCL-SIM membrane showed formation of significantly more ectopic cementum-like mineral on the dentin surface. These findings demonstrated that the PCL-SIM membrane scaffold promotes cementum-like tissue formation by sustained drug release, suggesting the feasibility of its therapeutic use with PDLSC sheets to improve periodontal regeneration.

Effects of statins on the biological features of mesenchymal stem cells and therapeutic implications

Statins are well-known lipid-lowering drugs. The pleiotropic effects of statins have brought about some beneficial effects on improving the therapeutic outcomes of cell therapy and tissue engineering approaches. In this review, the impact of statins on mesenchymal stem cell behaviors including differentiation, apoptosis, proliferation, migration, and angiogenesis, as well as molecular pathways which are responsible for such phenomena, are discussed. A better understanding of pathways and mechanisms of statin-mediated effects on mesenchymal stem cells will pave the way for the expansion of statin applications. Furthermore, since designing a suitable carrier for statins is required to maintain a sufficient dose of active statins at the desired site of the body, different systems for local delivery of statins are also reviewed.

Application of nanoparticles in bone tissue engineering; a review on the molecular mechanisms driving osteogenesis

The introduction of nanoparticles into bone tissue engineering strategies is beneficial to govern cell fate into osteogenesis and the regeneration of large bone defects. The present study explored the role of nanoparticles to advance osteogenesis with a focus on the cellular and molecular pathways involved. Pubmed, Pubmed Central, Embase, Scopus, and Science Direct databases were explored for those published articles relevant to the involvement of nanoparticles in osteogenic cellular pathways. As multifunctional compounds, nanoparticles contribute to scaffold-free and scaffold-based tissue engineering strategies to progress osteogenesis and bone regeneration. They regulate inflammatory responses and osteo/angio/osteoclastic signaling pathways to generate an osteogenic niche. Besides, nanoparticles interact with biomolecules, enhance their half-life and bioavailability. Nanoparticles are promising candidates to promote osteogenesis. However, the interaction of nanoparticles with the biological milieu is somewhat complicated, and more considerations are recommended on the employment of nanoparticles in clinical applications because of NP-induced toxicities.

Simvastatin-loaded polymeric micelles are more effective and less toxic than conventional statins in a pre-clinical model of advanced chronic liver disease

Chronic liver disease (CLD) has no effective treatments apart from reducing its complications. Simvastatin has been tested as vasoprotective drug in experimental models of CLD showing promising results, but also limiting adverse effects. Two types of Pluronic® carriers loading simvastatin (PM108-simv and PM127-simv) as a drug delivery system were developed to avoid these toxicities while increasing the therapeutic window of simvastatin. PM127-simv showed the highest rates of cell internalization in rat liver sinusoidal endothelial cells (LSECs) and significantly lower toxicity than free simvastatin, improving cell phenotype. The in vivo biodistribution was mainly hepatic with 50% of the injected PM found in the liver. Remarkably, after one week of administration in a model of CLD, PM127-simv demonstrated superior effect than free simvastatin in reducing portal hypertension. Moreover, no signs of toxicity of PM127-simv were detected. Our results indicate that simvastatin targeted delivery to LSEC is a promising therapeutic approach for CLD.

Evaluation of effect of two different functionalized nanoparticle photodynamic therapy on nanohardness of root dentin-An in vitro study

INTRODUCTION

The aim of this study was to evaluate the effect of functionalized nanoparticle photodynamic therapy on Nano hardness of root dentin METHODOLOGY: Fifty single rooted lower premolars were decoronated and sectioned into two halves. Then the samples were embedded horizontally in to the acrylic resin to expose the dentin surface. Baseline nanohardness was done at midroot level using a Nanohardness tester. Exposed dentin surfaces were immersed in the following irrigating solutions Post treatment nanohardness testing was done and results were analyzed statistically RESULTS: In general, all the samples in their respective groups had significant change in nanohardness following immersion in irrigant solutions except in NaOCl + EDTA and saline group. CSRB-np and PLGA-MBnp showed increased nanohardness (P = 0.005 and P = 0.007 respectively). Whereas NaOCl + EDTA + CHX showed decrease in nanohardness (P = 0.04). With regards to Modulus of elasticity (MOE), CSRB-np showed significant difference (P = 0.002) compared to the other groups. MOE increased in CSRB-np and PLGA-MBnp while it decreased in all the other groups.

CONCLUSION

In this study, the improvement of nanohardness and modulus of elasticity following the immersion of root dentin in CSRB-np solution was demonstrated.

Review of craniofacial regeneration in China

AIM

Tissue engineering has been recognised as one of the most effective means to form a new viable tissue for medical purpose. Tissue engineering involves a combination of scaffolds, cells, suitable biochemical and physicochemical factors, and engineering and materials methods. This review covered some biomedicine, such as biomaterials, bioactive factors, and stem cells, and manufacturing technologies used in tissue engineering in the oral maxillofacial region, especially in China.

MATERIALS AND METHODS

Data for this review were identified by searches of Web of Science and PubMed, and references from relevant articles using the search terms "biomaterials", "oral tissue regeneration", "bioactive factors" and "stem cells". Only articles published in English between 2013 and 2018 were included.

CONCLUSION

The combination of stem cells, bioactive factors and 3D scaffolds could be of far-reaching significance for the future therapies in tissue repair or tissue regeneration. Furthermore, the review also mentions issues that need to be solved in the application of these biomedicines.

Combination of a Bioceramic Scaffold and Simvastatin Nanoparticles as a Synthetic Alternative to Autologous Bone Grafting

The fragile nature of porous bioceramic substitutes cannot match the toughness of bone, which limits the use of these materials in clinical load-bearing applications. Statins can enhance bone healing, but it could show rhabdomyolysis/inflammatory response after overdosing. In this study, the drug-containing bone grafts were developed from poly(lactic acid-co-glycolic acid)-polyethylene glycol (PLGA-PEG) nanoparticles encapsulating simvastatin (SIM) (SIM-PP NPs) loaded within an appropriately mechanical bioceramic scaffold (BC). The combination bone graft provides dual functions of osteoconduction and osteoinduction. The mechanical properties of the bioceramic are enhanced mainly based on the admixture of a combustible reverse-negative thermoresponsive hydrogel (poly(N-isopropylacrylamide base). We showed that SIM-PP NPs can increase the activity of alkaline phosphatase and osteogenic differentiation of bone marrow stem cells. To verify the bone-healing efficacy of this drug-containing bone grafts, a nonunion radial endochondral ossification bone defect rabbit model (N = 3/group) and a nonunion calvarial intramembranous defect Sprague Dawley (SD) rat model (N = 5/group) were used. The results indicated that SIM-PP NPs combined with BC can improve the healing of nonunion bone defects of the radial bone and calvarial bone. Therefore, the BC containing SIM-PP NPs may be appropriate for clinical use as a synthetic alternative to autologous bone grafting that can overcome the problem of determining the clinical dosage of simvastatin drugs to promote bone healing.

Bone-targeted delivery of simvastatin-loaded PEG-PLGA micelles conjugated with tetracycline for osteoporosis treatment

This study aimed to investigate the improved therapeutic efficacy and pharmacokinetic profiles of simvastatin (SIM) with imparted bone targeting potential using tetracycline-mediated PEG-PLGA (TC-PEG-PLGA) micelles in osteoporotic rats. The SIM-loaded TC-PEG-PLGA (TC-PEG-PLGA/SIM) micelles were evaluated for particle size, morphology, stability, loading efficiency, cell viability, bone mineral binding ability in vitro, mineralization, pharmacokinetics, and pharmacodynamics. TC-PEG-PLGA conjugates were successfully and could self-assembly form micelles in aqueous medium with a 19.4 μg/mL critical micelle concentration. Then, TC-PEG-PLGA/SIM micelles were prepared with solvent diffusion method, and the obtained micelles (56.21 ± 7.39 nm average size; 81.8 ± 3.1% encapsulation efficiency; and 7.56 ± 0.27% drug loading) led to the prolonged release of SIM from micelles. Cellular uptake test indicated that TC had no effects on micellar internalization and micellar internalization was mainly involved with clathrin-mediated endocytic pathway. In vivo pharmacokinetic results indicated that TC-PEG-PLGA/SIM micelles exhibited a significantly prolonged time in systemic circulation and were preferentially accumulated in bone tissue. TC-PEG-PLGA/SIM micelles showed better therapeutic effects, as reflected by the improved bone mineral density, bone mineral content, and bone mechanical strength. Overall, these results suggested that TC-PEG-PLGA/SIM micelles provide several advantages, including prolonged systemic circulation, enhanced bone tissue distribution, and improved therapeutic outcomes in osteoporotic rats.

Enhancement of Bone Marrow-Derived Mesenchymal Stem Cell Osteogenesis and New Bone Formation in Rats by Obtusilactone A

The natural pure compound obtusilactone A (OA) was identified in Cinnamomum kotoense Kanehira & Sasaki, and shows effective anti-cancer activity. We studied the effect of OA on osteogenesis of bone marrow-derived mesenchymal stem cells (BMSCs). OA possesses biocompatibility, stimulates Alkaline Phosphatase (ALP) activity and facilitates mineralization of BMSCs. Expression of osteogenesis markers BMP2, Runx2, Collagen I, and Osteocalcin was enhanced in OA-treated BMSCs. An in vivo rat model with local administration of OA via needle implantation to bone marrow-residing BMSCs revealed that OA increased the new bone formation and trabecular bone volume in tibias. Micro-CT images and H&E staining showed more trabecular bone at the needle-implanted site in the OA group than the normal saline group. Thus, OA confers an osteoinductive effect on BMSCs via induction of osteogenic marker gene expression, such as BMP2 and Runx2 expression and subsequently elevates ALP activity and mineralization, followed by enhanced trabecular bone formation in rat tibias. Therefore, OA is a potential osteoinductive drug to stimulate new bone formation by BMSCs.

Atorvastatin-loaded micelles with bone-targeted ligand for the treatment of osteoporosis

Osteoporosis is a common bone disorder where the declined bone mass is far more than normal physiological status and usually associated with enhanced fracture risk, reduced bone strength and even deteriorated quality of life. Recent studies showed that statins could exert beneficial effects on bones via promoting osteoblastic activity mediated by increased expression of bone morphogenetic protein 2 and also by suppressing osteoclast proliferation. In this study, we developed atorvastatin-loaded tetracycline-poly (ethylene glycol)-poly(lactic-co-glycolic acid) (TC-PEG-PLGA/ATO) micelles for the targeted treatment of osteoporosis. The TC-PEG-PLGA was synthesized under the action of coupling reagents and then ATO was encapsulated through solvent diffusion method with encapsulation efficiency and drug loading of 89.32 ± 2.48% and 8.20 ± 0.53%, respectively. The release of ATO from micelles could be maintained for more than 48 h in pH 7.4 PBS. Pharmacokinetic results further demonstrated that TC-PEG-PLGA micelles could effectively shield ATO leakage from micelles and prolong their circulation time. Benefiting from TC specifically binding to hydroxyapatite (HAp), TC-PEG-PLGA/ATO micelles exerted good bone-targeted ability, as demonstrated by in vitro HAp affinity assay and biodistribution. Pharmacodynamic studies showed that TC-PEG-PLGA/ATO micelles could effectively improve bone mineral density and bone mechanical strength in osteoporotic rats. These results suggest that TC-PEG-PLGA/ATO micelles hold significant promise for the targeted treatment of osteoporosis.

Evaluations of clinical-grade bone substitute-combined simvastatin carriers to enhance bone growth: In vitro and in vivo analyses

We demonstrated in a value-added study that the combination of calcium phosphate–based bone substitute (MaxiBone® bioceramics) and simvastatin/poly lactic- co-glycolic acid (SIMm) carriers which were fabricated by GMP pharmaceutical company and underwent our patterned double-emulsion technique can promote bone growth. The average size distribution of SIMm, the encapsulation efficacy, and the in vitro release profile of simvastatin in SIMm over 14 days were investigated in this study. Based on the results of Alizarin Red S staining and alkaline phosphatase activity, the released simvastatin of SIMm can effectively induce osteogenesis of bone marrow mesenchymal stem cells (D1 cells). In the non-union fracture model of animal study, the MaxiBone bioceramics group and MaxiBone bioceramics with SIMm group showed a significant increase in the percentages of new bone matrix compared with the control group and SIMm groups at the 8th and 10th weeks. Moreover, the MaxiBone bioceramics with SIMm group showed the strongest effect in new bone formation among these groups. We concluded that the calcium phosphate–based ceramics of MaxiBone combined with SIMm can accelerate osteogenic differentiation and bone growth in vitro and in vivo. Our results provide a proof of concept that SIMm can play as an osteoinductive material and the combination with bone substitutes with osteoconductive property effectively enhance bone growth, and this treatment is value added for clinical application, especially in the healing of large bone defects or non-union.

Graphical abstract. The clinical-grade calcium phosphate–based bone substitute combined SIM/PLGA/HAp microspheres were fabricated by GMP pharmaceutical company to promote bone growth in bone defect model of mice.

Synthesis, characterisation and preliminary investigation of the haemocompatibility of poly(d,l-lactide-co-glycolide)–poly(ethyleneglycol)–poly(d,l-lactide-co-glycolide) copolymer for simvastatin delivery

The development of nanomedicine has provided advanced treatment opportunities for many diseases. Simvastatin, a widely used anti-lipidaemic drug, has potential for the treatment of orthopaedic diseases. However, the clinical application of simvastatin is limited because of its hydrophobicity and lack of distribution in osseous tissue. In this study, an amphiphilic nanoparticle, poly(d,l-lactide- co-glycolide)–poly(ethyleneglycol)–poly(d,l-lactide- co-glycolide), was synthesised to improve the biocompatibility of simvastatin. The haemocompatibility of the poly(d,l-lactide- co-glycolide)–poly(ethyleneglycol)–poly(d,l-lactide- co-glycolide) copolymer was investigated through its aggregation, morphology and lysis of human red blood cells, along with its impact on the clotting function according to the activated partial thromboplastin time, prothrombin time and thromboelastographic assays. The results demonstrated that the poly(d,l-lactide- co-glycolide)–poly(ethyleneglycol)–poly(d,l-lactide- co-glycolide) copolymer with a concentration lower than 10 mg/mL had little impact on the aggregation, morphology or lysis of red blood cells, or on blood coagulation. Therefore, the copolymer may be a strong alternative candidate as an effective and safe drug carrier.

Nanocapsules engineered from polyhedral ZIF-8 templates for bone-targeted hydrophobic drug delivery

A novel bone-targeted delivery systems based on nanocapsules was developed utilizing a Zeolitic Imidazolate Framework (ZIF-8) as a template and catechol-modified gelatin as wall material. A targeting ligand was facilely conjugated on the surface of nanocapsules. Simvastatin was encapsulated within the nanocapsules with a loading of 37.9%. Hydroxyapatite binding and in vivo biodistribution of the drug-loaded nanocapsules were investigated.

Photoluminescent polyphosphazene nanoparticles for in situ simvastatin delivery for improving the osteocompatibility of BMSCs

Photoluminescent prodrug nanoparticles for BMSCs’ endocytosis to improve osteogenesis via in situ simvastatin delivery resulting from polyphosphazene hydrolysis.

Osteogenic/Odontogenic Bioengineering with co-Administration of Simvastatin and Hydroxyapatite on Poly Caprolactone Based Nanofibrous Scaffold

Purpose: Statin is an effective factor for promoting osteogenesis. The aim of the present study was to evaluate the effect of simvastatin (SIM) and/or HA addition on changes in osteogenesis levels by human DPSCs transferred onto three-dimensional (3D) nanofibrous Poly (ε-caprolactone) (PCL)/Poly lactic acide (PLLA) polymeric scaffolds. Methods: For this purpose, a 3D nanofibrous composite scaffold of PCL/PLLA/HA was prepared by electrospinning method. SIM was added to scaffolds during DPSCs culturing step. Cell proliferation and osteogenic activity levels were assessed by using MTT assay and Alizarin Red assay methods. In addition, the expression of genes responsible for osteogenesis, including BMP2, Osteocalcin, DSPP and RUNX2, were determined before and 2 weeks after incorporation of SIM. Results: The MTT assay showed that PCL/PLLA/HA scaffolds seeded with DPSCs has significant (p<0.05) more proliferative effect than PCL/PLLA or DMEM cultured cells, additionally SIM administration improved this result over the PCL/PLLA/HA scaffolds without SIM treatment. SEM imaging revealed improved adhesion and probably osteogenic differentiation of DPSCs on PCL/PLLA/HA nanofibers treated with SIM, moreover the alizarin red assay ensured significant (p<0.05) higher mineralization of this group. Finally, real time PCR confirmed the positive regulation (P<0.05) of the expression of osteo/odontogenesis markers BMP2, Osteocalcin, DSPP and RUNX2 genes in PLLA-PCL-HA (0.1)-SIM group. Conclusion: As a result, addition of simvastatin with incorporation of hydroxyapatite in PCL-PLLA scaffolds might increase the expression of osteogenesis markers in the DPSCs, with a possible increase in cell differentiation and bone formation.

Nanoparticle-mediated co-delivery of chemotherapeutic agent and siRNA for combination cancer therapy

INTRODUCTION

Cancer is the leading cause of death worldwide. Current cancer treatments in the clinic mainly include chemotherapy, radiotherapy and surgery, with chemotherapy being the most common. Areas covered: Cancer treatments based on the single 'magic-bullet' concept are often associated with limited therapeutic efficacy, unwanted adverse effects, and drug resistance. The combination of multiple drugs is a promising strategy for effective cancer treatment due to the synergistic or additive effects. Small interfering RNA (siRNA) has the ability to knock down the expression of carcinogenic genes or drug efflux transporter genes, paving the way for cancer treatment. Treatment with both a chemotherapeutic agent and siRNA based on nanoparticle (NP)-mediated co-delivery is a promising approach for combination cancer therapy. Expert opinion: The combination of chemotherapeutic agents and siRNAs for cancer treatment offers the potential to enhance therapeutic efficacy, decrease side effects, and overcome drug resistance. Co-delivery of chemical drug and siRNA in the same NP would be much more effective in cancer therapy than application of chemical agent or siRNA alone. With the development of material science, NPs have come to be the most widely used platform for co-delivery of chemotherapeutic drugs and siRNAs.

PNIPAAM modified mesoporous hydroxyapatite for sustained osteogenic drug release and promoting cell attachment

This work presented a sustained release system of simvastatin (SIM) based on the mesoporous hydroxyapatite (MHA) capped with poly(N-isopropylacrylamide) (PNIPAAM). The MHA was prepared by using cetyltrimethylammonium bromide (CTAB) as a template and the modified PNIPAAM layer on the surface of MHA was fabricated through surface-initiated atom transfer radical polymerization (SI-ATRP). The SIM loaded MHA-PNIPAAM showed a sustained release of SIM at 37 °C over 16 days. The bone marrow mesenchymal stem cell (BMSC) proliferation was assessed by cell counting kit-8 (CCK-8) assay, and the osteogenic differentiation was evaluated by alkaline phosphatase (ALP) activity and Alizarin Red staining. The release profile showed that the release of SIM from MHA-SIM-PNIPAAM lasted 16 days and the cumulative amount of released SIM was almost seven-fold than MHA-SIM. Besides, SIM loaded MHA-PNIPAAM exhibited better performance on cell proliferation, ALP activity, and calcium deposition than pure MHA due to the sustained release of SIM. The quantity of ALP in MHA-SIM-PNIPAAM group was more than two fold than pure MHA group at 7 days. Compared to pure MHA, better BMSC attachment on PNIPAAM modified MHA was observed using fluorescent microscopy, indicating the better biocompatibility of MHA-PNIPAAM.

Simvastatin improves the homing of BMSCs via the PI3K/AKT/miR-9 pathway

Bone marrow‐derived mesenchymal stem cells (BMSCs) have great therapeutic potential for many diseases. However, the homing of BMSCs to injury sites remains a difficult problem. Recent evidence indicates that simvastatin stimulates AKT phosphorylation, and p‐AKT affects the expression of chemokine (CXC motif) receptor‐4 (CXCR4). Therefore, simvastatin may improve the expression of CXCR4 in BMSCs, and microRNAs (miRs) may participate in this process. In this study, we demonstrated that simvastatin increased both the total and the surface expression of CXCR4 in BMSCs. Stromal cell‐derived factor‐1α (SDF‑1α)‐induced migration of BMSCs was also enhanced by simvastatin, and this action was inhibited by AMD 3100(a chemokine receptor antagonist for CXCR4). The PI3K/AKT pathway was activated by simvastatin in this process, and LY294002 reversed the overexpression of CXCR4 caused by simvastatin. MiR‐9 directly targeted CXCR4 in rat BMSCs, and simvastatin decreased miR‐9 expression. P‐AKT affected the expression of miR‐9; as the phosphorylation of AKT increased, miR‐9 expression decreased. In addition, LY294002 increased miR‐9 expression. Taken together, our results indicated that simvastatin improved the migration of BMSCs via the PI3K/AKT pathway. MiR‐9 also participated in this process, and the phosphorylation of AKT affected miR‐9 expression, suggesting that simvastatin might have beneficial effects in stem cell therapy.

Organic Nanomaterials and Their Applications in the Treatment of Oral Diseases

There is a growing interest in the development of organic nanomaterials for biomedical applications. An increasing number of studies focus on the uses of nanomaterials with organic structure for regeneration of bone, cartilage, skin or dental tissues. Solid evidence has been found for several advantages of using natural or synthetic organic nanostructures in a wide variety of dental fields, from implantology, endodontics, and periodontics, to regenerative dentistry and wound healing. Most of the research is concentrated on nanoforms of chitosan, silk fibroin, synthetic polymers or their combinations, but new nanocomposites are constantly being developed. The present work reviews in detail current research on organic nanoparticles and their potential applications in the dental field.

Tetracycline-grafted PLGA nanoparticles as bone-targeting drug delivery system

Purpose

Nanoparticles (NPs) that target bone tissue were developed using poly(lactic-co-glycolic acid) (PLGA) copolymers and tetracycline (TC)-based bone-targeting moieties. These NPs are expected to enable the transport of drugs, such as simvastatin (SIM), for the treatment of osteoporosis.

Methods

The molecular structures of TC–PLGA were validated by ¹H-NMR, and the SIM-loaded NPs were prepared using the solvent emulsification method. The surface properties, cytotoxicity, cellular uptake, cell mineralization, bone targeting potential, and animal pharmacodynamics of the TC–PLGA NPs were evaluated and compared to those of PLGA NPs.

Results

It was confirmed that the average particle size of the NPs was approximately 220 nm. In phosphate-buffered saline (PBS, pH 7.4), the SIM-loaded NPs exhibited a cumulative release of up to 80% within 72 hours. An in vitro cell evaluation indicated that the NPs had an excellent cellular uptake capacity and showed great biocompatibility with MC3T3-E1 cells, thereby reducing the cytotoxic effects of SIM. The cell mineralization assay showed that the SIM-loaded NPs induced osteogenic differentiation and mineralized nodule formation in MC3T3-E1 cells, thereby achieving the same effect as SIM. Preliminary findings from in vitro and in vivo bone affinity assays indicated that the TC–PLGA NPs may display increased bone-targeting efficiency compared to PLGA NPs lacking a TC moiety. The use of SIM-loaded TC–PLGA NPs in treating osteoporosis was tested through animal pharmacodynamics analyses performed in ovariectomized rats, and the results suggested that the SIM-loaded TC–PLGA NPs can improve the curative effects of SIM on the recovery of bone mineral density compared to either SIM-loaded PLGA NPs or SIM alone.

Conclusion

Bone-targeting NPs, which were based on the conjugation of TC to PLGA copolymers, have the ability to target bone. These NPs may be developed as a delivery system for hydrophobic drugs, and they are expected to improve the curative effects of drugs, reduce the administered drug doses, and reduce side effects in other organs.

Delivery of baicalein and paclitaxel using self-assembled nanoparticles: synergistic antitumor effect in vitro and in vivo

Purpose

Combination anticancer therapy is promising to generate synergistic anticancer effects to maximize the treatment effect and overcome multidrug resistance. The aim of the study reported here was to develop multifunctional, dual-ligand, modified, self-assembled nanoparticles (NPs) for the combination delivery of baicalein (BCL) and paclitaxel (PTX) prodrugs.

Methods

Prodrug of PTX and prodrug of BCL, containing dual-targeted ligands of folate (FA) and hyaluronic acid (HA), were synthesized. Multifunctional self-assembled NPs for combination delivery of PTX prodrug and BCL prodrug (PTX-BCL) were prepared and the synergistic antitumor effect was evaluated in vitro and in vivo. The in vitro transfection efficiency of the novel modified vectors was evaluated in human lung cancer A549 cells and drug-resistant lung cancer A549/PTX cells. The in vivo antitumor efficiency and systemic toxicity of different formulations were further investigated in mice bearing A549/PTX drug-resistant human lung cancer xenografts.

Results

The size of the PTX-BCL NPs was approximately 90 nm, with a positive zeta potential of +3.3. The PTX-BCL NPs displayed remarkably better antitumor activity over a wide range of drug concentrations, and showed an obvious synergism effect with CI₅₀ values of 0.707 and 0.513, indicating that double-ligand modification and the co-delivery of PTX and BCL prodrugs with self-assembled NPs had remarkable superiority over other formulations.

Conclusion

The prepared PTX-BCL NP drug-delivery system was proven efficient by its targeting of drug-resistant human lung cancer cells and delivering of BCL and PTX prodrugs. Enhanced synergistic anticancer effects were achieved by PTX-BCL NPs, and multidrug resistance of PTX was overcome by this promising targeted nanomedicine.

Targeted lung cancer therapy: preparation and optimization of transferrin-decorated nanostructured lipid carriers as novel nanomedicine for co-delivery of anticancer drugs and DNA

Purpose

Nanostructured lipid carriers (NLC) represent an improved generation of lipid nanoparticles. They have specific nanostructures to accommodate drugs/genes, and thus achieve higher loading capacity. The aim of this study was to develop transferrin (Tf)-decorated NLC as multifunctional nanomedicine for co-delivery of paclitaxel (PTX) and enhanced green fluorescence protein plasmid.

Methods

Firstly, Tf-conjugated ligands were synthesized. Secondly, PTX- and DNA-loaded NLC (PTX-DNA-NLC) was prepared. Finally, Tf-containing ligands were used for the surface decoration of NLC. Their average size, zeta potential, drug, and gene loading were evaluated. Human non-small cell lung carcinoma cell line (NCl-H460 cells) was used for the testing of in vitro transfection efficiency, and in vivo transfection efficiency of NLC was evaluated on mice bearing NCl-H460 cells.

Results

Tf-decorated PTX and DNA co-encapsulated NLC (Tf-PTX-DNA-NLC) were nano-sized particles with positive zeta potential. Tf-PTX-DNA-NLC displayed low cytotoxicity, high gene transfection efficiency, and enhanced antitumor activity in vitro and in vivo.

Conclusion

The results demonstrated that Tf-PTX-DNA-NLC can achieve impressive antitumor activity and gene transfection efficiency. Tf decoration also enhanced the active targeting ability of the carriers to NCl-H460 cells. The novel drug and gene delivery system offers a promising strategy for the treatment of lung cancer.

Current Uses of Poly(lactic-co-glycolic acid) in the Dental Field: A Comprehensive Review

Poly(lactic-co-glycolic acid) or PLGA is a biodegradable polymer used in a wide range of medical applications. Specifically PLGA materials are also developed for the dental field in the form of scaffolds, films, membranes, microparticles, or nanoparticles. PLGA membranes have been studied with promising results, either alone or combined with other materials in bone healing procedures. PLGA scaffolds have been used to regenerate damaged tissues together with stem cell-based therapy. There is solid evidence that the development of PLGA microparticles and nanoparticles may be beneficial to a wide range of dental fields such as endodontic therapy, dental caries, dental surgery, dental implants, or periodontology. The aim of the current paper was to review the recent advances in PLGA materials and their potential uses in the dental field.

Nanocarrier mediated delivery of siRNA/miRNA in combination with chemotherapeutic agents for cancer therapy: current progress and advances

Chemotherapeutic agents have certain limitations when it comes to treating cancer, the most important being severe side effects along with multidrug resistance developed against them. Tumor cells exhibit drug resistance due to activation of various cellular level processes viz. activation of drug efflux pumps, anti-apoptotic defense mechanisms, etc. Currently, RNA interference (RNAi) based therapeutic approaches are under vibrant scrutinization to seek cancer cure. Especially small interfering RNA (siRNA) and micro RNA (miRNA), are able to knock down the carcinogenic genes by targeting the mRNA expression, which underlies the uniqueness of this therapeutic approach. Recent research focus in the regime of cancer therapy involves the engagement of targeted delivery of siRNA/miRNA in combinations with other therapeutic agents (such as gene, DNA or chemotherapeutic drug) for targeting permeability glycoprotein (P-gp), multidrug resistant protein 1 (MRP-1), B-cell lymphoma (BCL-2) and other targets that are mainly responsible for resistance in cancer therapy. RNAi-chemotherapeutic drug combinations have also been found to be effective against different molecular targets as well and can increase the sensitization of cancer cells to therapy several folds. However, due to stability issues associated with siRNA/miRNA suitable protective carrier is needed and nanotechnology based approaches have been widely explored to overcome these drawbacks. Furthermore, it has been univocally advocated that the co-delivery of siRNA/miRNA with other chemodrugs significantly enhances their capability to overcome cancer resistance compared to naked counterparts. The objective of this article is to review recent nanocarrier based approaches adopted for the delivery of siRNA/miRNA combinations with other anticancer agents (siRNA/miRNA/pDNA/chemodrugs) to treat cancer.