Association between alcohol dehydrogenase polymorphisms (rs1229984, rs1573496, rs1154460, and rs284787) and susceptibility to head and neck cancers: A systematic review and meta-analysis.

OBJECTIVE: Head and neck cancer (HNC) is a prevalent and complex group of malignancies with increasing incidence globally. Alcohol dehydrogenases (ADHs) play a crucial role in alcohol metabolism, and their polymorphisms have been linked to HNC risk. This systematic review and meta-analysis aims to evaluate the association between ADH polymorphisms and susceptibility to HNCs, incorporating additional analyses and adding more studies to increase power and accuracy of the results. DESIGN: Subgroup analysis, meta-regression analysis, and sensitivity analyses were conducted to explore potential differences within the data and assess the stability of pooled odds ratios (ORs). To mitigate the risk of false conclusions from meta-analyses, a trial sequential analysis was performed. RESULTS: For ADH1B rs1229984, the pooled OR (95 % confidence interval (CI)) was 0.73 (0.65, 0.82), 0.42 (0.35, 0.50), 0.57 (0.44, 0.73), 0.56 (0.50, 0.62), and 0.80 (0.73, 0.88), as well as for ADH7 rs1573496, the pooled OR was 0.72 (0.62, 0.85), 0.36 (0.17, 0.74), 0.76 (0.64, 0.91), 0.80 (0.71, 0.91), and 0.38 (0.18, 0.78) with a p < 0.05 in all allelic, homozygous, heterozygous, recessive, and dominant models, respectively. However, no significant association was found between the ADH7 rs1154460 and rs284787 polymorphisms and the risk of HNC with pooled ORs of 1.11 (p = 0.19) and 1.09 (p = 0.24) for the recessive model, respectively. The ethnicities, tumor subsites, control sources, sample sizes, quality scores, and Hardy-Weinberg equilibrium statuses were confounding factors. CONCLUSION: The ADH1B rs1229984 and ADH7 rs1573496 polymorphisms are significantly associated with a reduced risk of HNC.

The wound healing effect of polycaprolactone-chitosan scaffold coated with a gel containing Zataria multiflora Boiss. volatile oil nanoemulsions.

AIMS: Thymus plant is a very useful herbal medicine with various properties such as anti-inflammatory and antibacterial. Therefore, the properties of this plant have made this drug a suitable candidate for wound healing. In this study, hydroxypropyl methylcellulose (HPMC) gel containing Zataria multiflora volatile oil nanoemulsion (neZM) along with polycaprolactone/chitosan (PCL-CS) nanofibrous scaffold was used, and the effect of three experimental groups on the wound healing process was evaluated. The first group, HPMC gel containing neZM, the second group, PCL-CS nanofibers, and the third group, HPMC gel containing neZM and bandaged with PCL-CS nanofibers (PCL-CS/neZM). Wounds bandaged with common sterile gas were considered as control. METHODS: The nanoemulsion was synthesized by a spontaneous method and loaded into a hydroxypropyl methylcellulose (HPMC) gel. The DLS test investigated the size of these nanoemulsions. A PCL-CS nanofibrous scaffold was also synthesized by electrospinning method then SEM and contact angle tests investigated morphology and hydrophilicity/hydrophobicity of its surface. The animal study was performed on full-thickness skin wounds in rats, and the process of tissue regeneration in the experimental and control groups was evaluated by H&E and Masson's trichrome staining. RESULTS: The results showed that the nanoemulsion has a size of 225±9 nm and has an acceptable dispersion. The PCL-CS nanofibers synthesized by the electrospinning method also show non-beaded smooth fibers and due to the presence of chitosan with hydrophilic properties, have higher surface hydrophobicity than PCL fibers. The wound healing results show that the PCL-CS/neZM group significantly reduced the wound size compared to the other groups on the 7th, 14th, and 21st days. The histological results also show that the PCL-CS/neZM group could significantly reduce the parameters of edema, inflammation, and vascularity and increase the parameters of fibrosis, re-epithelialization, and collagen deposition compared to other groups on day 21. CONCLUSION: The results of this study show that the PCL-CS/neZM treatment can effectively improve wound healing.

Liposomal nanocarriers containing siRNA as small molecule-based drugs to overcome cancer drug resistance.

This review discusses the application of nanoliposomes containing siRNA/drug to overcome multidrug resistance for all types of cancer treatments. As drug resistance-associated factors are overexpressed in many cancer cell types, pumping chemotherapy drugs out of the cytoplasm leads to an inadequate therapeutic response. The siRNA/drug-loaded nanoliposomes are a promising approach to treating multidrug-resistant cancer, as they can effectively transmit a small-molecule drug into the target cytoplasm, ensuring that the drug binds efficiently. Moreover, nanoliposome-based therapeutics with advances in nanotechnology can effectively deliver siRNA to cancer cells. Overall, nanoliposomes have the potential to effectively deliver siRNA and small-molecule drugs in a targeted manner and are thus a promising tool for the treatment of cancer and other diseases.

Advantages of Material Biofunctionalization Using Nucleic Acid Aptamers in Tissue Engineering and Regenerative Medicine.

Material engineering is a fundamental issue in the applications of materials in the medical field. One of the aspects of material engineering is incorporating recognition sites on the surface of biomaterials, which plays an essential role in increasing the efficiency of tissue engineering scaffolds in various aspects. The application of peptides and antibodies to establish the recognition and adhesion sites has limitations, such as fragility and instability under physical and chemical processes. Therefore, synthetic ligands such as nucleic acid aptamers have received much attention for easy synthesis, minimal immunogenicity, high specificity, and stability under processing. Due to the effective role of these ligands in increasing the efficiency of engineered constructs in this study, the advantages of nucleic acid aptamers in tissue engineering will be reviewed. Aptamer-functionalized biomaterials can attract endogenous stem cells to wounded areas and organize their actions to facilitate tissue regeneration. This approach harnesses the body's inherent regeneration potential to treat many diseases. Also, increased efficacy in controlled release, slow and targeted drug delivery are important issues in drug delivery for tissue engineering approaches which can be achieved by incorporating aptamers in drug delivery systems. Aptamer-functionalized scaffolds have very applications, such as diagnosis of cancer, hematological infections, narcotics, heavy metals, toxins, controlled release from the scaffolds, and in vivo cell tracing. Aptasensors, as a result of many advantages over other traditional assay methods, can replace older methods. Furthermore, their unique targeting mechanism also targets compounds with no particular receptors. Targeting cell homing, local and targeted drug delivery, cell adhesion efficacy, cytocompatibility and bioactivity of scaffolds, aptamer-based biosensor, and aptamer-functionalized scaffolds are the topics that will be examined in this review study.

Salivary and serum levels of soluble E-cadherin in patients with gastrointestinal cancers: A comparative study.

AIM: According to the literature, high levels of salivary soluble E-cadherin may be lined to advanced stage and poor prognosis in cancers. This research aimed at comparing salivary and serum levels of soluble E-cadherin in cases with esophageal, gastric, and colorectal cancers. METHODS: This case-control research was performed on 68 patients with gastrointestinal cancers and 57 healthy volunteers as a control group to measure salivary and serum levels of soluble E-cadherin using ELISA kits. RESULTS: The results showed a statistically significant difference between salivary and serum levels of soluble E-cadherin in the case group, as opposed to the control group (P = 0.031). The salivary level of soluble E-cadherin in the control group was 2.138 ng/mL on average lower than that that in the case group. The median salivary level of soluble E-cadherin among cases with lymph node involvement was significantly higher compared with its median level in the control group (P = 0.049). Soluble E-cadherin salivary level and other variables, such as metastasis and cancer stage, were directly correlated, but it was not statistically significant. CONCLUSION: According to the findings, the salivary level of soluble E-cadherin among cases with gastric cancer could be considered as a prognostic marker, but the diagnostic value of saliva could not be judged in esophageal and colorectal cancers because of small sample size, and more investigations are required for a definite conclusion.

Enzyme-sensitive nanoparticles, smart TAT and cetuximab conjugated immunoliposomes to overcome multidrug resistance in breast cancer cells.

Due to recent advances in the field of small molecule-based drugs, designing an efficient siRNA delivery system seems essential. Here, modified sets of lipids conjugated with cell-penetrating TAT peptide, MMP2 enzyme-sensitive moiety, and cetuximab antibodies against the EGF receptor were synthesized, purified and verified on HPLC, TLC, SEM, and DLS analyses. Different cellular and molecular experiments were designed to evaluate the transfection efficiency, targeting properties, and functions, including cytotoxicity assay, resensitization assessments, flow cytometry-based uptake assay, BCRP silencing efficiency, real-time PCR, and western blotting. The final targeted liposomes represented an average diameter of 160 nm; zeta-potential and siRNA encapsulation rates were respectively around -28.9 ± 3.16 mV and 88.3 ± 0.9 w/w. The siBCRP carried by the TAT+Cetuximab+ liposome led to an increase in the tumoricidal effect of mitoxantrone by a reduction in IC50 value by 4-fold (*** P < 0.001). Flow cytometry results showed that the cellular uptake rate of final immunoliposomes was significantly higher than the naked liposomes (*** P < 0.001). The Targeted siRNA encapsulating liposomes decreased BCRP transcript and protein levels in MCF7-MX cells by 0.24 and 0.2-fold after 48 h, respectively. Due to the silencing results of the BCRP by the encapsulated siRNA and the inhibitory effects of cetuximab on the EGFR, this formulation could widely be utilized as a carrier for tumor-directed gene delivery.

A Randomized Triple-Blind Clinical Trial of the Effect of Low-Level Laser Therapy on Infiltration Injection Pain in the Anterior Maxilla

Abstract Objective: To evaluate the level of pain experienced during infiltration anesthesia of the anterior maxilla following low-level laser therapy (LLLT) with 810-980 nm wavelengths. Material and Methods: In the current triple-blind clinical trial, 84 patients received a total of 168 infiltration anesthesia injections (1.8 mL of 2% lidocaine plus 1:100,000 epinephrine) in the anterior maxilla. Each patient received two injections into the buccal mucosa of the right and left central incisors with a two-week interval. One injection was performed after LLLT, while the other injection was administered conventionally without laser. The pain level was measured immediately after injection using a visual analog scale (VAS). Results: There was a significant difference in the pain level experienced with and without LLLT, such that the mean pain score following LLLT was significantly lower than that without LLLT (p<0.05). No significant difference was found in the pain level between laser and no laser groups in males, but the difference in this regard was significant in females (p<0.05) and female patients experienced a significantly lower level of pain following LLLT. Conclusion: The low-level laser therapy can be successfully used to decrease the level of pain experienced during infiltration anesthesia of the anterior maxilla (AU).

The association of VEGF rs833061 and rs2010963 polymorphisms with susceptibility to colorectal cancer in an Iranian population.

Vascular endothelial growth factor (VEGF) is one of the most important regulators of angiogenesis. Several single nucleotide polymorphisms (SNPs) are associated with the VEGF overexpression and tumor progression in several cancers. This study aimed to determine the association of VEGF rs833061 and rs2010963 polymorphism and their haplotypes with susceptibility to colorectal cancer (CRC) in the Iranian population. A total of 284 colorectal cancer patients (37.3% women, 62.7% men) were enrolled in this study. Healthy controls without evidence of cancer history or family cancer predispositions were frequency-matched to the cases by sex and age (± 5 years). Genotyping was performed by the Sequenom mass ARRAY method and the genotype distribution and risk estimate were analyzed by SPSS software. The correlation between the genotypes and clinicopathological parameters (Dukes stage, phenotype, location, differentiation, and tumor size) among colorectal cancer patients were investigated. We found a significant relationship, between rs833061T/C genotype and their TG haplotype with the age of diagnosis < 60; (p = 0.012, p = 0.014) and rs2010963G/C genotype with female gender and TG haplotype with third and fourth tumor stage and tumor location (p = 0.04and p = 0.047). This study showed that rs833061T/C genotype and TG haplotype increase the susceptibility to colon cancer in the Iranian population. This susceptibility has a significant relationship with the age of diagnosis and different stages of the tumor.

A PRISMA-compliant meta-analysis on association between X-ray repair cross complementing (XRCC1, XRCC2, and XRCC3) polymorphisms and oral cancer susceptibility.

BACKGROUND: Oral Cancer (OC) is one of the leading causes of death and the disease mainly occurs over 50 years of age. Herein, a meta-analysis aimed to assess the association between X-ray repair cross complementing (XRCC) polymorphisms and OC risk. METHODS: Four databases were searched extensively until June 5, 2020. Subgroup analysis, meta-regression, and funnel plots, as well as the quality assessment were estimated. RESULTS: Fifteen studies were entered to the analysis. With regards to allele, homozygote, heterozygote, recessive, and dominant models, the pooled ORs for XRCC1 rs1799782 polymorphism were 1.51 (P = 0.01), 1.45 (P = 0.11), 1.45 (P = 0.0003), 1.44 (P = 0.0002), and 1.29 (P = 0.26); for XRCC1 rs1799782 polymorphism were 1.65 (P = 0.11), 1.50 (P = 0.33), 1.06 (P = 0.83), 1.57 (P = 0.12), and 1.32 (P = 0.45); for XRCC1 rs25489 polymorphism were 0.01 (P = 0.19), 1.44 (P = 0.48), 1.21 (P = 0.72), 1.17 (P = 0.19), and 1.38 (P = 0.54); for XRCC2 rs2040639 polymorphism were 0.68 (P = 0.0002), 0.63 (P = 0.02), 0.95 (P = 0.92), 0.79 (P = 0.49), and 0.61 (P = 0.005); and for XRCC3 rs861539 polymorphism were 1.24 (P = 0.20), 1.28 (P = 0.48), 0.99 (P = 0.95), 1.15 (P = 0.46), and 1.52 (P = 0.15), respectively. CONCLUSIONS: The T allele and CT genotype of XRCC1 rs1799782 polymorphism had an elevated risk, whereas the G allele and GG genotype of XRCC2 rs2040639 polymorphism had a protective role in OC.

Vibration Stimulation as a Non-Invasive Approach to Monitor the Severity of Meniscus Tears.

Musculoskeletal disorders and injuries are one of the most prevalent medical conditions across age groups. Due to a high load-bearing function, the knee is particularly susceptible to injuries such as meniscus tears. Imaging techniques are commonly used to assess meniscus injuries, though this approach suffers from limitations including high cost, need for skilled personnel, and confinement to laboratory or clinical settings. Vibration-based structural monitoring methods in the form of acoustic emission analysis and vibration stimulation have the potential to address the limits associated with current diagnostic technologies. In this study, an active vibration measurement technique is employed to investigate the presence and severity of meniscus tear in cadaver limbs. In a highly controlled ex vivo experimental design, a series of cadaver knees (n =6) were evaluated under an external vibration, and the frequency response of the joint was analyzed to differentiate the intact and affected samples. Four stages of knee integrity were considered: baseline, sham surgery, meniscus tear, and meniscectomy. Analyzing the frequency response of injured legs showed significant changes compared to the baseline and sham stages at selected frequency bandwidths. Furthermore, a qualitative analytical model of the knee was developed based on the Euler-Bernoulli beam theory representing the meniscus tear as a change in the local stiffness of the system. Similar trends in frequency response modulation were observed in the experimental results and analytical model. These findings serve as a foundation for further development of wearable devices for detection and grading of meniscus tear and for improving our understanding of the physiological effects of injuries on the vibration characteristics of the knee. Such systems can also aid in quantifying rehabilitation progress following reconstructive surgery and / or during physical therapy.

Synthetic biology in various cellular and molecular fields: applications, limitations, and perspective.

Synthetic biology breakthroughs have facilitated genetic circuit engineering to program cells through novel biological functions, dynamic gene expressions, as well as logic controls. SynBio can also participate in the rapid development of new treatments required for the human lifestyle. Moreover, these technologies are applied in the development of innovative therapeutic, diagnostic, as well as discovery-related methods within a wide range of cellular and molecular applications. In the present review study, SynBio applications in various cellular and molecular fields such as novel strategies for cancer therapy, biosensing, metabolic engineering, protein engineering, and tissue engineering were highlighted and summarized. The major safety and regulatory concerns about synthetic biology will be the environmental release, legal concerns, and risks of the engineered organisms. The final sections focused on limitations to SynBio.

Engineering mesenchymal stem cells: a novel therapeutic approach in breast cancer.

Breast cancer is one of the most prevalent and deadliest cancers among women in the world because of its aggressive behaviour and inadequate response to conventional therapies. Cellular and gene therapies based on mesenchymal stem cells (MSCs) represent promising treatment strategies for multiple diseases, such as cancers. MSCs are multipotent adult stem cells with important features for cell therapy, such as tissue homing to injured sites, their differentiation potential, their capacity of secreting plenty of trophic factors, and low immunogenicity. The quite easy isolation of these cells from various types of tissues are associated with no ethical concern when dealing with foetal or embryonic stem cells. The MSCs exhibit both pro and anti-oncogenic properties. However, genetic engineering of MSCs and nanoparticles is being employed as a means to solve some of these problems and improve the antitumor properties of these cells. The tumour-homing ability of MSCs and their exosomes to tumour niches have made them as a promising vector for targeted delivery of therapeutic agents to tumours site. The present study investigated MSCs specifications, pro- and anti-oncogenic properties of MSCs in breast cancer, and reviewed targeted breast cancer therapy via engineered MSCs, likely as potent cellular vehicles.

Association between cystathionine beta-synthase c.844ins68 polymorphism and risk of non-syndromic cleft lip/palate: A meta-analysis of family-based and case-control studies.

OBJECTIVE: Both genetics and environmental factors play a role in the occurrence of non-syndromic cleft lip/palate (NSCL/P). This meta-analysis evaluated the association between cystathionine beta-synthase (CBS) c.844ins68 polymorphism and risk of NSCL/P in family-based and case-control studies. MATERIALS AND METHODS: The PubMed, Web of Science, Scopus, and Cochrane Library databases were searched for articles published until September 2018. RevMan 5.3 software was used to calculate the odds ratio (OR) for the association between CBS c.844ins68 polymorphism and risk of NSCL/P by using five genetic models in the studies. The transmission disequilibrium test (TDT) was conducted for family-based studies. RESULTS: Three case-control and three family-based studies were evaluated. Based on the analysis of five genetic models, risk of NSCL/P was not related to CBS c.844ins68 polymorphism in case-control studies. The results of family-based studies did not show any association between the CBS c.844ins68 allele and NSCL/P either. CONCLUSIONS: The results of this meta-analysis showed that there was no association between CBS c.844ins68 polymorphism and risk of NSCL/P; therefore, this polymorphism does not play a role in susceptibility to NSCL/P.

Serum and salivary interleukin-4 levels in patients with oral lichen planus: A systematic review and meta-analysis.

OBJECTIVE: Cytokines have an important role in keratinocyte immune damage and can act in the pathogenesis of different cutaneous diseases. Accordingly, in the literature, interleukin 4 (IL-4) concentration has been previously investigated in patients affected by oral lichen planus (OLP). STUDY DESIGN: The present meta-analysis evaluated the serum and salivary levels of IL-4 in connection with several OLP variants. The search was performed from 1995 in Cochrane Library and 1983 in Scopus, PubMed, and Web of Science to September 2018. The quality of the studies included in the meta-analysis was assessed using the Newcastle-Ottawa Scale assessment. The analyses were done by Review Manager 5.3 using mean difference (MD) and 95% confidence intervals (CIs). RESULTS: Out of 108 studies retrieved in the databases, only 10 were included and analyzed in quantitative synthesis. The pooled MD of the serum and salivary IL-4 levels in OLP patients compared with the controls was 6.36 picograms/milliliter (pg/mL) (95% CI: 1.47, 11.24; P = .01) and 2.67 pg/mL (95% CI: 2.66, 2.68; P < .00001), respectively. In addition, the pooled MD of serum and salivary IL-4 level was 1.30 pg/mL (95% CI: -0.35, 2.95; P = .12) and 1.83 pg/mL (95% CI: 0.26, 3.40; P = .02), respectively, in patients with erosive, erythematous, bullous, and ulcerative variants of OLP compared with patients with reticular OLP. CONCLUSIONS: This meta-analysis found that OLP patients present elevated serum and salivary IL-4 levels, thus indicating that IL-4 may represent a potential salivary biomarker for the disease. By contrast, clinicians must be aware that even other factors (e.g., secondary infection) may influence its concentration.

Applying the Taguchi Method to the Optimization of Anticancer Activity of Bacterial Alginate-CuO Bionanocomposite.

AIM: In recent decades, despite various types of cancer inflicting many people worldwide, the existing therapies are not satisfactory and have many side effects. The present study was conducted to optimise the synthesis of novel alginate-CuO nanocomposite with utmost anticancer activity. METHODS: In this study, 9 nanocomposites were designed using Taguchi method and three factors including copper oxide nanoparticles, alginate biopolymer and stirring times were assessed at three different levels. The anticancer activity of the synthesised nanocomposites was evaluated on the MCF-7 cell line using the MTT method. Using the Qulitek-4 software, we determined the optimum conditions for the synthesis of alginate-CuO nanocomposite with the highest anticancer activity. RESULTS: The results indicated that all three factors (copper oxide, alginate and stirring time) were effective on the anticancer activity of the alginate-CuO nanocomposite. Also, the nanocomposite produced under the conditions of experiment 9 (8 mg/ml of copper oxide, 2 mg/ml of alginate and 60 min of stirring time) provided the highest growth inhibition rate as 75.63% against cancer cells. CONCLUSION: The synthesised alginate-copper oxide nanocomposites in this study showed a significant anticancer effect. Therefore, the synthesised nanocomposite under optimal conditions can be used in the design of new anticancer drugs.

Force detection, center of pressure tracking, and energy harvesting from a piezoelectric knee implant.

Recent developments in the field of orthopedic materials and procedures have made the total knee replacement (TKR) an option for people who suffer from knee diseases and injuries. One of the ongoing debates in this area involves the correlation of postoperative joint functionality to intraoperative alignment. Due to a lack of in vivo data from the knee joint after surgery, the establishment of a well-quantified alignment method is hindered. In order to obtain information about knee function after the operation, the design of a self-powered instrumented knee implant is proposed in this study. The design consists of a total knee replacement bearing equipped with four piezoelectric transducers distributed in the medial and lateral compartments. The piezoelectric transducers are utilized to measure the total axial force applied on the tibial bearing through the femoral component of the joint, as well as to track the movement in the center of pressure (CoP). In addition, the generated voltage from the piezoelectrics can be harvested and stored to power embedded electronics for further signal conditioning and data transmission purposes. Initially, finite element (FE) analysis is performed on the knee bearing to select the best location of the transducers with regards to sensing the total force and location of the CoP. A series of experimental tests are then performed on a fabricated prototype which aim to investigate the sensing and energy harvesting performance of the device. Piezoelectric force and center of pressure measurements are compared to actual experimental quantities for twelve different relative positions of the femoral component and bearing of the knee implant in order to evaluate the performance of the sensing system. The output voltage of the piezoelectric transducers is measured across a load resistance to determine the optimum extractable power, and then rectified and stored in a capacitor to evaluate the realistic energy harvesting ability of the system. The results show only a small level of error in sensing the force and the location of the CoP. Additionally, a maximum power of 269.1 µW is achieved with a 175 kΩ optimal resistive load, and a 4.9 V constant voltage is stored in a 3.3 mF capacitor after 3333 loading cycles. The sensing and energy harvesting results present the promising potential of this system to be used as an integrated self-powered instrumented knee implant.

Energy Harvesting and Sensing with Embedded Piezoelectric Ceramics in Knee Implants.

The knee replacement is one of the most common orthopedic surgical interventions in the United States; however, recent studies have shown up to 20% of patients are dissatisfied with the outcome. One of the key issues to improving these operations is a better understanding of the ligamentous balance during and after surgery. The goal of this work is to investigate the feasibility of embedding piezoelectric transducers in the polyethylene bearing of a total knee replacement to act as self-powered sensors to aid in the alignment and balance of the knee replacement by providing intra- and postoperative feedback to the surgeon. A model consisting of a polyethylene disc with a single embedded piezoelectric ceramic transducer is investigated as a basis for future work. A modeling framework is developed including a biomechanical model of the knee joint, a finite element model of the knee bearing with encapsulated transducer, and an electromechanical model of the piezoelectric transducer. Model predictions show that a peak voltage of 2.3 V with a load resistance of 1.01 MΩ can be obtained from a single embedded piezoelectric stack, and an average power of 12 µW can be obtained from a knee bearing with four embedded piezoelectric transducers. Uniaxial compression testing is also performed on a fabricated sample for model validation. The results found in this work show promising potential of embedded piezoelectric transducers to be utilized for autonomous, self-powered in vivo knee implant force sensors.

Parametric analysis of electromechanical and fatigue performance of total knee replacement bearing with embedded piezoelectric transducers.

Total knee arthroplasty (TKA) is a common procedure in the United States; it has been estimated that about 4 million people are currently living with primary knee replacement in this country. Despite huge improvements in material properties, implant design, and surgical techniques, some implants fail a few years after surgery. A lack of information about in vivo kinetics of the knee prevents the establishment of a correlated intra- and postoperative loading pattern in knee implants. In this study, a conceptual design of an ultra high molecular weight (UHMW) knee bearing with embedded piezoelectric transducers is proposed, which is able to measure the reaction forces from knee motion as well as harvest energy to power embedded electronics. A simplified geometry consisting of a disk of UHMW with a single embedded piezoelectric ceramic is used in this work to study the general parametric trends of an instrumented knee bearing. A combined finite element and electromechanical modeling framework is employed to investigate the fatigue behavior of the instrumented bearing and the electromechanical performance of the embedded piezoelectric. The model is validated through experimental testing and utilized for further parametric studies. Parametric studies consist of the investigation of the effects of several dimensional and piezoelectric material parameters on the durability of the bearing and electrical output of the transducers. Among all the parameters, it is shown that adding large fillet radii results in noticeable improvement in the fatigue life of the bearing. Additionally, the design is highly sensitive to the depth of piezoelectric pocket. Finally, using PZT-5H piezoceramics, higher voltage and slightly enhanced fatigue life is achieved.

Application of Various Types of Liposomes in Drug Delivery Systems.

Liposomes, due to their various forms, require further exploration. These structures can deliver both hydrophilic and hydrophobic drugs for cancer, antibacterial, antifungal, immunomodulation, diagnostics, ophtalmica, vaccines, enzymes and genetic elements. Preparation of liposomes results in different properties for these systems. In addition, based on preparation methods, liposomes types can be unilamellar, multilamellar and giant unilamellar; however, there are many factors and difficulties that affect the development of liposome drug delivery structure. In the present review, we discuss some problems that impact drug delivery by liposomes. In addition, we discuss a new generation of liposomes, which is utilized for decreasing the limitation of the conventional liposomes.