Effect of Curcumin-Loaded Mesoporous Silica Nanoparticles on the Head and Neck Cancer Cell Line, HN5.

Curcumin is an active ingredient isolated from Curcuma longa. It has several pharmacological effects, including anticancer, anti-inflammatory, and antioxidant effects. Due to its low bioavailability, chemical structure instability, and easy oxidation, the application of curcumin has been limited. In this study, to overcome these limitations, curcumin-loaded mesoporous silica nanoparticles (Cur-MSN) were prepared, and the anticancerous effect of Cur-MSNs on head and neck cancer cells, HN5, was investigated. Transmission electron microscopy (TEM) revealed rod-shaped mesoporous nanoparticles with average particle size smaller than 100 nm. Higher cytotoxicity of Cur-MSNs was seen in treated cancer cells compared with free curcumin. The expression of Bcl-2 was significantly reduced in the presence of Cur-MSNs compared to the control (untreated HN5 cells) (p < 0.05). A 3.43-fold increase in the Bax/Bcl-2 ratio was seen in Cur-MSNs treated HN5 cells at the IC50. Cur-MSNs increased intracellular reactive oxygen species (ROS) production. Based on these novel results, we suggest that Cur-MSNs offer efficacy for cancer treatment and future studies should further characterize their properties in various experimental cancer models.

Antibacterial Effect of Co-Loaded Curcumin and Rutin in Mesoporous Silica Nanoparticles Compared to their Loading Alone.

AIMS: The present study aimed to assess the antibacterial effect of co-loaded rutin and curcumin in mesoporous silica nanoparticles (Cur-Rut-MSNs). BACKGROUND: Rutin is a nontoxic phytochemical that is present expansively in vegetables and fruits. Curcumin is an active ingredient of Curcuma longa. Curcumin and rutin have a variety of therapeutic effects, essentially antimicrobial, anti-inflammatory, and antioxidant actions. OBJECTIVE: Low aqueous solubility and poor bioavailability of rutin and curcumin limit their application in therapeutic goals. One of the advantageous routes to improve their bioavailability and solubility is nanoformulation. Co-delivery of therapeutic agents has been reported to have better therapeutic effects than monotherapy. METHODS: The present study has evaluated the antibacterial properties of Cur-Rut-MSNs. The Minimum Inhibitory Concentration (MIC) of Cur-Rut-MSNs has been assessed against different bacteria. RESULTS: Cur-Rut-MSNs exerted significantly higher antibacterial effect than curcumin-loaded MSNs (Cur-MSNs) and rutin-loaded MSNs (Rut-MSNs) against Acinetobacter baumannii, Escherichia coli, Staphylococcus aureus, and Enterococcus faecalis (p<0.05). CONCLUSION: The antibacterial effect was enhanced by the co-loading of rutin and curcumin in MSNs. According to the findings of this study, Cur-Rut-MSNs exhibit an antibacterial effect and can be a favorable nanoformulation against planktonic bacteria.

Nanocurcumin-containing Spongy Membrane for Improving the Quality of Hard and Soft Tissues in the Extracted Tooth Area: A Double-Blind Split- Mouth Clinical Trial Study.

BACKGROUND: The assessment of the hard and soft tissue conditions is part of the overall dental treatments. AIM: In this study, we investigated nano curcumin-containing membranes to improve the quality of the hard and soft tissues in the extracted tooth area as a clinical trial study. METHODS: After the patient was selected following the inclusion and exclusion criteria, the patients who had teeth extracted from both sides of the mouth (split mouth) on the side of the intervention received a membrane containing nanocurcumin, and on the control side, no material was placed in the socket. For data analysis, SPSS software version 24 was used. A significance threshold was deemed to be less than 0.05 in terms of probability. RESULTS: Two months after tooth extraction, during implant placement, the average gingival thickness on the "intervention side," was 3.1±0.34 mm, while the average gingival thickness on the "control side" was 2.6±0.42 mm. Then, the membrane could improve the quality of soft tissue (P< 0.0001). As another outcome, the application of this membrane did not significantly affect bone repair in these patients compared to the control group (P = 0.72). However, the histology data revealed that the newly generated bone of the intervention group was seen close to the membrane, demonstrating the osteoconductive ability of the membrane. CONCLUSION: Based on the obtained results, the newly developed membrane can be used to improve the quality of hard and soft tissues in the extracted tooth area. Nonetheless, more efforts in nanocurcumin dosage adjustment are needed for hard tissue regeneration in future studies.

Introducing effective genes in lymph node metastasis of breast cancer patients using SHAP values based on the mRNA expression data.

OBJECTIVE: Breast cancer, a global concern predominantly impacting women, poses a significant threat when not identified early. While survival rates for breast cancer patients are typically favorable, the emergence of regional metastases markedly diminishes survival prospects. Detecting metastases and comprehending their molecular underpinnings are crucial for tailoring effective treatments and improving patient survival outcomes. METHODS: Various artificial intelligence methods and techniques were employed in this study to achieve accurate outcomes. Initially, the data was organized and underwent hold-out cross-validation, data cleaning, and normalization. Subsequently, feature selection was conducted using ANOVA and binary Particle Swarm Optimization (PSO). During the analysis phase, the discriminative power of the selected features was evaluated using machine learning classification algorithms. Finally, the selected features were considered, and the SHAP algorithm was utilized to identify the most significant features for enhancing the decoding of dominant molecular mechanisms in lymph node metastases. RESULTS: In this study, five main steps were followed for the analysis of mRNA expression data: reading, preprocessing, feature selection, classification, and SHAP algorithm. The RF classifier utilized the candidate mRNAs to differentiate between negative and positive categories with an accuracy of 61% and an AUC of 0.6. During the SHAP process, intriguing relationships between the selected mRNAs and positive/negative lymph node status were discovered. The results indicate that GDF5, BAHCC1, LCN2, FGF14-AS2, and IDH2 are among the top five most impactful mRNAs based on their SHAP values. CONCLUSION: The prominent identified mRNAs including GDF5, BAHCC1, LCN2, FGF14-AS2, and IDH2, are implicated in lymph node metastasis. This study holds promise in elucidating a thorough insight into key candidate genes that could significantly impact the early detection and tailored therapeutic strategies for lymph node metastasis in patients with breast cancer.

Preparation, Characterization, and Evaluation of the Anticancer Effect of Mesoporous Silica Nanoparticles Containing Rutin and Curcumin.

AIMS AND OBJECTIVE: The aim of this study was the preparation of mesoporous silica nanoparticles co-loaded with rutin and curcumin (Rut-Cur-MSNs) and the assessment of its physicochemical properties as well as its cytotoxicity on the head and neck cancer cells (HN5). Besides, ROS generation of HN5 cells exposed to Rut-Cur-MSNs was evaluated. Several investigations showed that rutin and curcumin have potential effects as anticancer phytochemicals; however, their low aqueous solubility and poor bioavailability limited their applications. The assessment of physicochemical properties and anticancer effect of prepared nanoparticles was the objective of this study. METHODS: The physicochemical properties of produced nanoparticles were evaluated. The toxicity of Rut-Cur-MSNs on HN5 cells was assessed. In addition, the ROS production in cells treated with Rut-Cur-MSNs was assessed compared to control untreated cells. RESULTS: The results showed that Rut-Cur-MSNs have mesoporous structure, nanometer size and negative surface charge. The X-ray diffraction pattern showed that the prepared nanoparticles belong to the family of silicates named MCM-41. The cytotoxicity of Rut-Cur-MSNs at 24 h was significantly higher than that of rutin-loaded MSNs (Rut-MSNs) and curcumin-loaded MSNs (Cur-MSNs) (p<0.05). CONCLUSION: The achieved results recommend that the prepared mesoporous silica nanoparticles containing rutin and curcumin can be a useful nanoformulation for the treatment of cancer. The produced nanomaterial in this study can be helpful for cancer therapy.

Effect of curcumin-containing nanofibrous gelatin-hydroxyapatite scaffold on proliferation and early osteogenic differentiation of dental pulp stem cells.

BACKGROUND: In recent years, the electrospinning method has received attention because of its usage in producing a mimetic nanocomposite scaffold for tissue regeneration. Hydroxyapatite and gelatin are suitable materials for producing scaffolds, and curcumin has the osteogenesis induction effect. AIMS: This study aimed to evaluate the toxicity and early osteogenic differentiation stimulation of nanofibrous gelatin-hydroxyapatite scaffold containing curcumin on dental pulp stem cells (DPSCs). OBJECTIVE: The objective of the present investigation was the evaluation of the proliferative effect and primary osteogenic stimulation of DPSCs with a nanofibrous gelatin-hydroxyapatite scaffold containing curcumin. Hydroxyapatite and gelatin were used as suitable and biocompatible materials to make a scaffold suitable for stimulating osteogenesis. Curcumin was added to the scaffold as an osteogenic differentiation-enhancing agent. METHODS: The effect of nano-scaffold on the proliferation of DPSCs was evaluated. The activity of alkaline phosphatase (ALP) as the early osteogenic marker was considered to assess primary osteogenesis stimulation in DPSCs. RESULTS: The nanofibrous gelatin-hydroxyapatite scaffold containing curcumin significantly increased the proliferation and the ALP activity of DPSCs (P<0.05). The proliferative effect was insignificant in the first 2 days, but the scaffold increased cell proliferation by more than 40% in the fourth and sixth days. The prepared scaffold increased the activity of the ALP of DPSCs by 60% compared with the control after 14 days (P<0.05). CONCLUSION: The produced nanofibrous gelatin-hydroxyapatite scaffold containing curcumin can be utilized as a potential candidate in tissue engineering and regeneration of bone and tooth. FUTURE PROSPECTS: The prepared scaffold in the present study could be a beneficial biomaterial for tissue engineering and the regeneration of bone and tooth soon.

The Antibacterial Effect of Tetracycline-loaded Mesoporous Silica Nanoparticles in the Gingival Fluid at Implant-abutment Junction: A Randomized Clinical Trial Study.

INTRODUCTION: Dental implant failure due to periodontal disease caused by anaerobic pathogens occurs, especially in the first year of implant placement. The aim of this clinical trial study was to compare the antibacterial effect of tetracycline gel and gel containing tetracyclineloaded mesoporous silica nanoparticles (MSNs) in the gingival crevice fluid of the implantabutment junction as a randomized clinical trial study. MATERIALS AND METHODS: Fourteen patients applying for implants in the posterior mandibular region were included in the study. During the uncovering session, tetracycline gel and gel containing tetracycline-loaded MSNs were placed in two implants and no substance was placed in the control group. Then, in three sessions, including molding, prosthesis delivery, and one month after delivery, the patient's gingival fluid was sampled and the number of bacteria in the gingival fluid was measured by colony-forming units (CFU/mL). RESULTS: The results of this study showed that in all three stages of sampling, the use of tetracycline gel and gel containing MSNs loaded with tetracycline significantly reduced the CFU/mL of gingival crevice fluid compared to the control group. Tetracycline-loaded MSNs gel showed significantly lower CFU/mL than tetracycline gel. The release of tetracycline from nanoparticles keep continue for a longer time compared to tetracycline gel. CONCLUSION: The use of nano-based delivery systems containing antibiotics inside the implant fixture can reduce the bacterial count of the implant-abutment junction and then improve implant stability.

The Sustained-released Polylactic Co-glycolic Acid Nanoparticles Loaded with Chlorhexidine as Antibacterial Agents Inside the Dental Implant Fixture.

INTRODUCTION: Titanium-based implants are widely used due to their good biocompatibility and high corrosion resistance. Infections after implant placement are the main reason for the failure of implant treatment. Some recent studies have also shown that microbial contamination can occur at the implant-abutment level in implants with healthy or diseased surrounding tissue. The purpose of this study is to investigate the antibacterial effect of slow-release nanoparticles of polylactic co-glycolic acid (PLGA) loaded with chlorhexidine (CHX) inside the implant fixture. MATERIALS AND METHODS: Thirty-six implants in three groups were examined in the bacterial culture environment. In the first group, PLGA/CHX nanoparticles; in the second group, the negative control group (distilled water) and in the third group, the positive control groups (chlorhexidine) were used. The bacterial suspensions, including Escherichia coli ATCC: 25922, Staphylococcus aureus ATCC: 6538 and Enterococcus faecalis ATCC: 29212 were used to investigate the antimicrobial effect of the prepared nanoparticles. RESULTS: The results showed that the use of PLGA/CHX nanoparticles significantly inhibited the growth of all three bacteria. Nanoparticles loaded with chlorhexidine had a significant decrease in the growth rate of all three bacteria compared to chlorhexidine and water. The lowest bacterial growth rate was observed in the Enterococcus faecalis/PLGA nanoparticles group, and the highest bacterial growth rate was observed in the Staphylococcus aureus/H2O group. CONCLUSION: The current study showed that the use of PLGA/CHX nanoparticles could significantly inhibit the growth of all three bacteria. Of course, the current study was conducted in vitro, and to obtain clinical results, we need to conduct a study on human samples. In addition, the results of this study showed that the chemical antimicrobial materials could be used in low concentrations and in a sustained- released manner in cases of dealing with bacterial infections, which can lead to better and targeted performance as well as reduce possible side effects.

Synthesis, characterization, and evaluation of Hesperetin nanocrystals for regenerative dentistry.

Hesperetin (HS), a metabolite of hesperidin, is a polyphenolic component of citrus fruits. This ingredient has a potential role in bone strength and the osteogenic differentiation. The bone loss in the orofacial region may occur due to the inflammation response of host tissues. Nanotechnology applications have been harshly entered the field of regenerative medicine to improve the efficacy of the materials and substances. In the current study, the hesperetin nanocrystals were synthesized and characterized. Then, the anti-inflammatory and antioxidative effects of these nanocrystals were evaluated on inflamed human Dental Pulp Stem Cells (hDPSCs) and monocytes (U937). Moreover, the osteoinduction capacity of these nanocrystals was assessed by gene and protein expression levels of osteogenic specific markers including RUNX2, ALP, OCN, Col1a1, and BSP in hDPSCs. The deposition of calcium nodules in the presence of hesperetin and hesperetin nanocrystals was also assessed. The results revealed the successful fabrication of hesperetin nanocrystals with an average size of 100 nm. The levels of TNF, IL6, and reactive oxygen species (ROS) in inflamed hDPSCs and U937 significantly decreased in the presence of hesperetin nanocrystals. Furthermore, these nanocrystals induced osteogenic differentiation in hDPSCs. These results demonstrated the positive and effective role of fabricated nanocrystal forms of this natural ingredient for regenerative medicine purposes.

Co-Delivery of Cisplatin and Curcumin Using Mesoporous Silica Nanoparticles to Improve their Anticancer Effects.

AIMS: This study aimed to prepare and evaluate the physicochemical and anticancer properties of cisplatin and curcumin-loaded mesoporous silica nanoparticles (Cis-Cur-MSNs). BACKGROUND: In recent years, combination treatment has attained better outcomes than monotherapy in oncology. Cis-Cur-MSNs were prepared by precipitation technique. OBJECTIVE: The objective of the present study was the evaluation of the physicochemical and anticancer properties of cisplatin and curcumin-loaded mesoporous silica nanoparticles (Cis-Cur-MSNs). METHODS: The prepared materials were assessed in terms of physicochemical methods. The drug release pattern from the MSNs was also evaluated via ultraviolet spectrophotometry. In addition, the porosity and surface area of prepared nanoparticles were determined using the Brunauer-Emmett-Teller (BET) technique. The cytotoxicity of Cis-Cur-MSNs was evaluated on the HN5 cells as head and neck squamous carcinoma cell lines. Furthermore, ROS production of Cis-Cur-MSNs treated cells was evaluated compared with untreated cells. RESULTS: According to the results, prepared nanoparticles displayed nanometer size, rod morphology, and negative surface charge with mesoporous structure belonging to the MCM-41 family (twodimensional hexagonal). Regarding the results of BET adsorption and desorption isotherm analysis for Cis-Cur-MSNs and drug-free MSNs, pore diameter, pore volume, specific surface area, and drug-loaded pore area in MSNs were decreased. In the first 10 days, the prepared nanoparticles exhibited a relatively rapid release pattern for cisplatin and curcumin, and until the 35th day, the release of them from the MSNs continued slowly. CONCLUSION: The cytotoxic effect of Cis-Cur-MSNs was significantly more than Cur-MSNs and Cis- MSNs in 24 and 48 h incubation time (p < 0.05). The results suggest that Cis-Cur-MSNs may be beneficial in the development of a cancer treatment protocol. Others: The prepared nanoparticle in the present study could be a potential biomaterial for cancer treatment.

Effect of Curcumin on the Head and Neck Squamous Cell Carcinoma Cell Line HN5.

BACKGROUND: Curcumin has been isolated from the rhizomes of Curcuma longa. Over the years, it has shown outstanding therapeutic potential in various human disorders, including cancers. OBJECTIVE: The aim is to study curcumin's effects on the apoptosis signaling pathway in the head and neck squamous cell carcinoma (HNSCC) cell line HN5. METHODS: The cytotoxicity of curcumin on HN5 cells were assessed. In addition, HN5 cells were also treated with curcumin to evaluate its effect on the caspase-8, -9, Bcl-2, Bax, and Stat3 gene expressions. RESULTS: The results exhibited that cell viability reduced following curcumin treatment in a concentration- dependent manner. Curcumin treatment caused decreased expression of Bcl2, with simultaneous upregulation of the Bax/Bcl2 ratio. Curcumin increased caspase-9 expression, did not affect caspase-8, and decreased Stat3 expression. The induction of the mitochondria-dependent apoptosis pathway of curcumin happened by modulating the expression of Bcl2 and Bax genes, resulting in the caspase-9 activation. Furthermore, curcumin decreased the expression of the Stat3 in HN-5 cells. CONCLUSIONS: In conclusion, curcumin showed marked anticancer effects in the HN-5 cell line by modulating Stat-3; Bax/Bcl-2 expression in vitro.

Safety issues of nanomaterials for dermal pharmaceutical products.

Nanomaterials (NMs) have favorable application in the medicine area, specifically in regard to the carry of pharmaceutical ingredients to provide targeted drug delivery systems. The skin is an excellent route for the delivery of pharmaceutical nano-transporters for skin-related applications. The physicochemical properties of nanomaterials such as size, hydrophobicity, loading capacity, charge and weight are vital for a skin penetrating system. Many nanocarriers such as polymeric nanoparticles, inorganic nanomaterials and, lipid nanostructures have been utilized for dermal delivery of active ingredients and others such as carbon nanotubes and fullerenes require more examination for future application in the skin-related area. Some negative side effects and nano-cytotoxicity of nanomaterials require special attention while investigating different nanomaterials for medicinal applications. Then, in the current review, we had a view on the safety issues of nanomaterials for dermal pharmaceutical products.

Antimicrobial Benefits of Flavonoids and their Nanoformulations.

Nowadays, there is an urgent need to discover and develop long-term and effective antimicrobial and biofilm-inhibiting compounds. Employing combination therapies using novel drug delivery systems and also natural antimicrobial substances is a promising strategy in this field. Nanoparticles (NPs)-based materials have become well appreciated in recent times due to their function as antimicrobial agents or carriers for promoting the bioavailability and effectiveness of antibiotics. Flavonoids belong to the promising groups of bioactive compounds abundantly found in fruits, vegetables, spices, and medicinal plants with strong antimicrobial features. Flavonoids and NPs have the potential to work as alternatives to the conventional antimicrobial agents, when used alone as well as in combination. Different classes of flavonoid NPs may be particularly advantageous in treating microbial infections. The most important antimicrobial mechanisms of flavonoid NPs include oxidative stress induction, non-oxidative mechanisms, and metal ion release. However, the efficacy of flavonoid NPs against pathogens and drug-resistant pathogens changes according to their physicochemical characteristics as well as the particular structure of microbial cell wall and enzymatic composition. In this review, we provide an outlook on the antimicrobial mechanism of flavonoid-based NPs and the crucial factors involved in it.

Application of Collagen and Mesenchymal Stem Cells in Regenerative Dentistry.

Collagen is an important macromolecule of Extracellular Matrix (ECM) in bones, teeth, and temporomandibular joints. Mesenchymal Stem Cells (MSCs) interact with the components of the ECM such as collagen, proteoglycans, Glycosaminoglycans (GAGs), and several proteins on behalf of variable matrix elasticity and bioactive cues. Synthetic collagen-based biomaterials could be effective scaffolds for regenerative dentistry applications due to mimicking of host tissues' ECM. These biomaterials are biocompatible, biodegradable, readily available, and non-toxic to cells whose capability promotes cellular response and wound healing in the craniofacial region. Collagen could incorporate other biomolecules to induce mineralization in calcified tissues like bone and tooth. Moreover, the addition of these molecules or other polymers to collagen-based biomaterials could enhance mechanical properties, which is important in load-bearing areas such as the mandible. A literature review was performed via a reliable internet database (mainly PubMed) based on MeSH keywords. This review first describes the properties of collagen as a key protein in the structure of hard tissues. Then, it introduces different types of collagens, the correlation between collagen and MSCs, and the methods used to modify collagen in regenerative dentistry, including recent progression on the regeneration of periodontium, dentin-pulp complex, and temporomandibular joint by applying collagen. The prospects and challenges of collagen-based biomaterials in the craniofacial region are pointd out.

Application of Nano-based Drug Loading Systems in the Treatment of Neurological Infections: An Updated Review.

Infection of the central nervous system (CNS) is a global healthcare concern with high rates of death and disease. CNS infections mainly include meningitis, encephalitis, and brain abscesses. Bacteria, viruses, fungi, protozoa, and parasites are the most common causes of neuroinfections. There are many types of medications used in the treatment of CNS infections, but drug delivery through the blood-brain barrier (BBB) is a major challenge to overcome. The BBB is a specialized multicellular barrier separating the neural tissue from the peripheral blood circulation. Unique characteristics of the BBB allow it to tightly control the movement of ions and molecules. Thus, there is a critical need to deal with these conditions with the aim of improving novel antimicrobial agents. Researchers are still struggling to find effective drugs to treat CNS infections. Nanoparticle (NP)-mediated drug delivery has been considered a profound substitute to solve this problem because NPs can be tailored to facilitate drug transport across the BBB. NPs are colloidal systems with a size range of 1-1000 nm, which can be used to encapsulate therapeutics, improve drug transport across the BBB, and target specific brain areas in CNS infections. A wide variety of NPs has been displayed for the CNS delivery of therapeutics, especially when their surfaces are coated with targeting moieties. This study aimed to review the available literature on the application of NPs in CNS infections.

The Link between Stroke Risk and Orodental Status-A Comprehensive Review.

One of the primary causes of disability and mortality in the adult population worldwide is stroke. A person's general health is significantly impacted by their oral and dental health. People who have poor oral health are more susceptible to conditions such as stroke. Stroke risk has long been linked to oral and dental conditions. The risk of stroke and its cost impact on the healthcare systems appear to be significantly reduced as a result of the decline in the incidence and prevalence of oral and dental illnesses. Hypothetically, better management of oral hygiene and dental health lead to reduced stroke risk. To the authors' best knowledge, for the first time, the potential link between dental health and stroke were cross-examined. The most typical stroke symptoms, oral and dental illnesses linked to stroke, and the role of oral healthcare professionals in stroke prevention are revealed. The potential mediating processes and subsequent long-term cognitive and functional neurological outcomes are based on the available literature. It must be noted that periodontal diseases and tooth loss are two common oral health measures. Lack of knowledge on the effects of poor oral health on systemic health together with limited access to primary medical or dental care are considered to be partially responsible for the elevated risk of stroke. Concrete evidence confirming the associations between oral inflammatory conditions and stroke in large cohort prospective studies, stratifying association between oral disease severity and stroke risk and disease effects on stroke survival will be desirable. In terms of clinical pathology, a predictive model of stroke as a function of oral health status, and biomarkers of systemic inflammation could be useful for both cardiologists and dentists.

Effect of different geometric changes in the dental implant abutment body on the amount of residual excess cement and retention in a cemented implant-supported prosthesis.

BACKGROUND: Fixed implant-supported restorations are mainly used in dental implantology. In comparison with screw-retained implants, cement-retained prostheses have the following advantages: the ease of splinting implants; increased passive casting; and procedural similarity to conventional tooth-supported fixed partial dentures. Furthermore, they show reduced fracturing of components with better esthetic outcomes and an improved force direction, along with a reduced cost and less chairside time. OBJECTIVES: The aim of this study was to evaluate the effect of different geometric changes in the dental implant abutment body on the amount of residual excess cement (REC) and the retention of cemented implant-supported prostheses. MATERIAL AND METHODS: Seventy-two straight abutments were categorized into 4 groups: vertical groove; 1 horizontal groove; 2 horizontal grooves; and ccontrol (with no geometric changes in the abutment). The access hole was partially filled and the cast copings were cemented using Temp-Bond™ NE, a non-eugenol cement. The difference in weight before and after removing the excess cement was considered as REC. Furthermore, the retention of the cast coping was measured as the force that was required to separate the cemented cast coping from the abutment. RESULTS: The mean REC values of the groups with 1 and 2 horizontal grooves were significantly different as compared to the control group (p < 0.05). CONCLUSIONS: This study shows that the presence of 1 or 2 horizontal grooves in the abutment body significantly reduces the amount of REC in comparison with control.

Safety and Toxicity Issues of Therapeutically Used Nanoparticles from the Oral Route.

The emerging science of nanotechnology sparked a research attention in its potential benefits in comparison to the conventional materials used. Oral products prepared via nanoparticles (NPs) have garnered great interest worldwide. They are used commonly to incorporate nutrients and provide antimicrobial activity. Formulation into NPs can offer opportunities for targeted drug delivery, improve drug stability in the harsh environment of the gastrointestinal (GI) tract, increase drug solubility and bioavailability, and provide sustained release in the GI tract. However, some issues like the management of toxicity and safe handling of NPs are still debated and should be well concerned before their application in oral preparations. This article will help the reader to understand safety issues of NPs in oral drug delivery and provides some recommendations to the use of NPs in the drug industry.

Antimicrobial and antibiofilm activities of meropenem loaded-mesoporous silica nanoparticles against carbapenem-resistant Pseudomonas aeruginosa.

The aims of the present study were the determination of antimicrobial and antibiofilm effects of meropenem-loaded mesoporous silica nanoparticles (MSNs) on carbapenem resistant Pseudomonas aeruginosa (P. aeruginosa) and cytotoxicity properties in vitro. The meropenem-loaded MSNs had shown antibacterial and biofilm inhibitory activities on all isolates at different levels lower than MICs and BICs of meropenem. The viability of HC-04 cells treated with serial concentrations as MICs and BICs of meropenem-loaded MSNs was 92-100%. According to the obtained results, meropenem-loaded MSNs display the significant antibacterial and antibiofilm effects against carbapenem resistant and biofilm forming P. aeruginosa and low cell toxicity in vitro. Then, the prepared system can be an appropriate option for the delivery of carbapenem for further evaluation in vivo assays.

Detection of pathogenic bacteria via nanomaterials-modified aptasensors.

Detection and identification of special cells via aptamer-based nano-conjugates sensors have been revolutionized over the past few years. These sensing platforms rely on selecting aptamers using systematic evolution of ligands by exponential enrichment (SELEX) in vitro, which allows for sensitive detection of cells. Integration of the aptamer-based sensors (aptasensors) with nanomaterials offers enhanced specificity and sensitivity, which in turn, offers great promise for numerous applications, spanning from bioanalysis to biomedical applications. Accordingly, the demand for using aptamer-conjugated nanomaterials for various applications has progressively increased over the past years. In light of this, this Review seeks to highlight the recent advances in the development of aptamer-conjugated nanomaterials and their utilization for the detection of various pathogens involved in infectious diseases and food contamination.