Insights into the Paulownia Shan tong (Fortunei × Tomentosa) Essential Oil and In Silico Analysis of Potential Biological Targets of Its Compounds

The volatile composition of Paulownia Shan tong (Fortunei × Tomentosa) essential oil isolated by steam distillation (yielding 0.013% v/w) from flowers (forestry wastes) was investigated by gas chromatography-mass spectrometry. Thirty-one components were identified, with 3-acetoxy-7, 8-epoxylanostan-11-ol (38.16%), β-monoolein (14.4%), lycopene, 1,2-dihydro-1-hydroxy- (10.21%), and 9,12-octadecadienoic acid, 2-phenyl-1,3-dioxan-5-yl ester (9.21%) as main compounds. In addition, molecular docking was employed to identify potential protein targets for the 31 quantified essential oil components. Inhibition of these targets is typically associated with antibacterial or antioxidant properties. Molecular docking revealed that six of these components, namely, 13-heptadecyn-1-ol, ascabiol, geranylgeraniol, anethole, and quinol dimethyl ether, outperformed the native ligand (hypoxanthine) of xanthine oxidase in terms of theoretical binding affinity, therefore implying a significant in silico inhibitory potential against xanthine oxidase. These findings suggest that the essential oil extracted from Paulownia Shan tong flowers could be valuable for developing protein-targeted antioxidant compounds with applications in the food, pharmaceutical, and cosmetic industries.

In silico and in vitro studies: investigating the chemical composition, DFT, molecular docking, and dynamic simulation of Satureja candidissima (Munby) Briq essential oil as a potential antibacterial agent

This study aimed to investigate the chemical composition and antibacterial properties of the essential oil (EO) derived from the aerial parts of Satureja candidissima (Munby) Briq (SC), as well as the mechanisms of interaction between SCEO chemical components and target proteins related to antibacterial activity mechanisms using a molecular docking approach, and for more accuracy molecular dynamic simulation and DFT calculations were carried out. The GC-MS technique was used to analyze the chemical composition of SCEO. The results showed that SCEO contained various chemical compounds, with pulegone being identified as the major component (53.26%). The results also indicated the presence of (+)-menthone (11.02%), borneol (4.43%), 2-cyclohexen-1-one, 3-methyl-6-(1-methylethylidene) (2.50%), and 3-octanol (2.09%). The study revealed that the SCEO displayed antibacterial activity against all tested gram-positive bacteria. To further understand the mechanism behind its antibacterial activity, in silico molecular docking studies were performed. The results indicated that the antibacterial effect of SCEO compounds could be due to the combination with enoyl-[acyl-carrier-protein] reductase [NADPH] FabI (PDB ID: 4ALL) in a variety of ways. The molecular dynamics simulation analysis yielded favorable outcomes for the docked complex involving 1H-cycloprop[e]azulen-7-ol, decahydro-1,1,7-trimethyl-4-methylene, and 1,4,7-tetramethyldecahydro-1H-cyclopropa[e]azulen-4-ol with enoyl-[acyl-carrier-protein] reductase [NADPH]. Geometry optimization, coupled with Density Functional Theory (DFT), can be employed to assess the importance of quantum chemical descriptors in elucidating potential antibacterial activity. Quantum descriptors were computed based on EHOMO and ELUMO. The results of this study provide important insights into the potential use of Satureja candidissima (Munby) Briq EO as antibacterial agent.Communicated by Ramaswamy H. Sarma.

Newly Synthesized CoFe2-xDyxO4 (x = 0; 0.1; 0.2; 0.4) Nanoparticles Reveal Promising Anticancer Activity against Melanoma (A375) and Breast Cancer (MCF-7) Cells

The current study focuses on the synthesis via combustion of dysprosium-doped cobalt ferrites that were subsequently physicochemically analyzed in terms of morphological and magnetic properties. Three types of doped nanoparticles were prepared containing different Dy substitutions and coated with HPGCD for higher dispersion properties and biocompatibility, and were later submitted to biological tests in order to reveal their potential anticancer utility. Experimental data obtained through FTIR, XRD, SEM and TEM confirmed the inclusion of Dy3+ ions in the nanoparticles' structure. The size of the newly formed nanoparticles ranged between 20 and 50 nm revealing an inverse proportional relationship with the Dy content. Magnetic studies conducted by VSM indicated a decrease in remanent and saturation mass magnetization, respectively, in Dy-doped nanoparticles in a direct proportionality with the Dy content; the decrease was further amplified by cyclodextrin complexation. Biological assessment in the presence/absence of red light revealed a significant cytotoxic activity in melanoma (A375) and breast (MCF-7) cancer cells, while healthy keratinocytes (HaCaT) remained generally unaffected, thus revealing adequate selectivity. The investigation of the underlying cytotoxic molecular mechanism revealed an apoptotic process as indicated by nuclear fragmentation and shrinkage, as well as by Western blot analysis of caspase 9, p53 and cyclin D1 proteins. The anticancer activity for all doped Co ferrites varied was in a direct correlation to their Dy content but without being affected by the red light irradiation.

The Antimelanoma Biological Assessment of Triterpenic Acid Functionalized Gold Nanoparticles

One of several promising strategies for increasing the bioavailability and therapeutic potential of high-lipophilic biologically active compounds is gold nanoparticle formulation. The current study describes the synthesis and biological antimelanoma evaluation of three triterpen-functionalized gold nanoparticles, obtained using our previously reported antimelanoma benzotriazole-triterpenic acid esters. Functionalized gold nanoparticle (GNP) formation was validated through UV-VIS and FTIR spectroscopy. The conjugate's cytotoxic effects were investigated using HaCaT healthy keratinocytes and A375 human melanoma cells. On A375 cells, all three conjugates demonstrated dose-dependent cytotoxic activity, but no significant cytotoxic effects were observed on normal HaCaT keratinocytes. GNP-conjugates were found to be more cytotoxic than their parent compounds. After treatment with all three GNP-conjugates, 4,6'-diamidino-2-phenylindole (DAPI) staining revealed morphological changes consistent with apoptosis in A375 melanoma cells. Quantitative real-time polymerase chain reaction (RT-qPCR) analysis revealed that the triterpene-GNP conjugate treated A375 melanoma cells had a fold change increase in Bcl-2-associated X protein (BAX) expression and a fold change decrease in B-cell lymphoma 2 (Bcl-2) expression. In A735 melanoma cells, high-resolution respirometry studies revealed that all three GNP-conjugates act as selective inhibitors of mitochondrial function. Furthermore, by examining the effect on each mitochondrial respiratory rate, the results indicate that all three conjugates are capable of increasing the production of reactive oxygen species (ROS), an apoptosis trigger in cancer cells.

The Anti-Melanoma Effect of Betulinic Acid Functionalized Gold Nanoparticles: A Mechanistic In Vitro Approach

Implementing metallic nanoparticles as research instruments for the transport of therapeutically active compounds remains a fundamentally vital work direction that can still potentially generate novelties in the field of drug formulation development. Gold nanoparticles (GNP) are easily tunable carriers for active phytocompounds like pentacyclic triterpenes. These formulations can boost the bioavailability of a lipophilic structure and, in some instances, can also enhance its therapeutic efficacy. In our work, we proposed a biological in vitro assessment of betulinic acid (BA)-functionalized GNP. BA-GNP were obtained by grafting BA onto previously synthesized citrate-capped GNP through the use of cysteamine as a linker. The nanoformulation was tested in HaCaT human keratinocytes and RPMI-7951 human melanoma cells, revealing selective cytotoxic properties and stronger antiproliferative effects compared to free BA. Further examinations revealed a pro-apoptotic effect, as evidenced by morphological changes in melanoma cells and supported by western blot data showing the downregulation of anti-apoptotic Bcl-2 expression coupled with the upregulation of pro-apoptotic Bax. GNP also significantly inhibited mitochondrial respiration, confirming its mitochondrial-targeted activity.

Semisynthetic Derivatives of Pentacyclic Triterpenes Bearing Heterocyclic Moieties with Therapeutic Potential

Medicinal plants have been used by humans since ancient times for the treatment of various diseases and currently represent the main source of a variety of phytocompounds, such as triterpenes. Pentacyclic triterpenes have been subjected to numerous studies that have revealed various biological activities, such as anticancer, antidiabetic, anti-inflammatory, antimicrobial, and hepatoprotective effects, which can be employed in therapy. However, due to their high lipophilicity, which is considered to exert a significant influence on their bioavailability, their current use is limited. A frequent approach employed to overcome this obstacle is the chemical derivatization of the core structure with different types of moieties including heterocycles, which are considered key elements in medicinal chemistry. The present review aims to summarize the literature published in the last 10 years regarding the derivatives of pentacyclic triterpenes bearing heterocyclic moieties and focuses on the biologically active derivatives as well as their structure-activity relationships. Predominantly, the targeted positions for the derivatization of the triterpene skeleton are C-3 (hydroxyl/oxo group), C-28 (hydroxyl/carboxyl group), and C-30 (allylic group) or the extension of the main scaffold by fusing various heterocycles with the A-ring of the phytocompound. In addition, numerous derivatives also contain linker moieties that connect the triterpenic scaffold with heterocycles; one such linker, the triazole moiety, stands out as a key pharmacophore for its biological effect. All these studies support the hypothesis that triterpenoid conjugates with heterocyclic moieties may represent promising candidates for future clinical trials.

A Combination of Two Probiotics, Lactobacillus sporogenes and Clostridium butyricum, Inhibits Colon Cancer Development: An In Vitro Study

Cancer remains a leading cause of death worldwide and, even though several advances have been made in terms of specific treatment, the late-stage detection and the associated side effects of the conventional drugs sustain the search for better treatment alternatives. Probiotics are live microorganisms that have been proven to possess numerous health benefits for human hosts, including anticancer effects. In the present study, the in vitro effect of the association of two probiotic strains (PBT), Lactobacillus sporogenes and Clostridium butyricum, were tested against colon (HT-29 and HCT 116), lung (A549), and liver (HepG2) cancer cell lines, alone or in combination with 5-fluorouracil (5FU). Moreover, the underlying mechanism of PBT and PBT-5FU against the HT-29 cell line was evaluated using the Hoechst 33342 staining, revealing characteristic apoptotic modifications, such as chromatin condensation, nuclear fragmentation, and membrane blebbing. Furthermore, the increase in the expression of pro-apoptotic Bax, Bid, Bad, and Bak proteins and the inhibition of the anti-apoptotic Bcl-2 and Bcl-XL proteins were recorded. Collectively, these findings suggest that the two strains of probiotic bacteria, alone or in association with 5FU, induce apoptosis in colon cancer cells and may serve as a potential anticancer treatment.

Recent Advances Regarding the Molecular Mechanisms of Triterpenic Acids: A Review (Part I)

Triterpenic acids are phytocompounds with a widespread range of biological activities that have been the subject of numerous in vitro and in vivo studies. However, their underlying mechanisms of action in various pathologies are not completely elucidated. The current review aims to summarize the most recent literature, published in the last five years, regarding the mechanism of action of three triterpenic acids (asiatic acid, oleanolic acid, and ursolic acid), corelated with different biological activities such as anticancer, anti-inflammatory, antidiabetic, cardioprotective, neuroprotective, hepatoprotective, and antimicrobial. All three discussed compounds share several mechanisms of action, such as the targeted modulation of the PI3K/AKT, Nrf2, NF-kB, EMT, and JAK/STAT3 signaling pathways, while other mechanisms that proved to only be specific for a part of the triterpenic acids discussed, such as the modulation of Notch, Hippo, and MALAT1/miR-206/PTGS1 signaling pathway, were highlighted as well. This paper stands as the first part in our literature study on the topic, which will be followed by a second part focusing on other triterpenic acids of therapeutic value.

The Optimized Delivery of Triterpenes by Liposomal Nanoformulations: Overcoming the Challenges

The last decade has witnessed a sustained increase in the research development of modern-day chemo-therapeutics, especially for those used for high mortality rate pathologies. However, the therapeutic landscape is continuously changing as a result of the currently existing toxic side effects induced by a substantial range of drug classes. One growing research direction driven to mitigate such inconveniences has converged towards the study of natural molecules for their promising therapeutic potential. Triterpenes are one such class of compounds, intensively investigated for their therapeutic versatility. Although the pharmacological effects reported for several representatives of this class has come as a well-deserved encouragement, the pharmacokinetic profile of these molecules has turned out to be an unwelcomed disappointment. Nevertheless, the light at the end of the tunnel arrived with the development of nanotechnology, more specifically, the use of liposomes as drug delivery systems. Liposomes are easily synthesizable phospholipid-based vesicles, with highly tunable surfaces, that have the ability to transport both hydrophilic and lipophilic structures ensuring superior drug bioavailability at the action site as well as an increased selectivity. This study aims to report the results related to the development of different types of liposomes, used as targeted vectors for the delivery of various triterpenes of high pharmacological interest.

The Role of Cyclodextrins in the Design and Development of Triterpene-Based Therapeutic Agents

Triterpenic compounds stand as a widely investigated class of natural compounds due to their remarkable therapeutic potential. However, their use is currently being hampered by their low solubility and, subsequently, bioavailability. In order to overcome this drawback and increase the therapeutic use of triterpenes, cyclodextrins have been introduced as water solubility enhancers; cyclodextrins are starch derivatives that possess hydrophobic internal cavities that can incorporate lipophilic molecules and exterior surfaces that can be subjected to various derivatizations in order to improve their biological behavior. This review aims to summarize the most recent achievements in terms of triterpene:cyclodextrin inclusion complexes and bioconjugates, emphasizing their practical applications including the development of new isolation and bioproduction protocols, the elucidation of their underlying mechanism of action, the optimization of triterpenes’ therapeutic effects and the development of new topical formulations.

Hollongdione arylidene derivatives induce antiproliferative activity against melanoma and breast cancer through pro-apoptotic and antiangiogenic mechanisms

The use of natural compounds as starting point for semisynthetic derivatives has already been proven as a valuable source of active anticancer agents. Hollongdione (4,4,8,14-tetramethyl-18-norpregnan-3,20-dion), obtained by few steps from dammarane type triterpenoid dipterocarpol, was chemically modified at C2 and C21 carbon atoms by the Claisen-Schmidt aldol condensation to give a series of arylidene derivatives. The anticancer activity of the obtained compounds was assessed on NCI-60 cancer cell panel, revealing strong antiproliferative effects against a large variety of cancer cells. 2,21-Bis-[3-pyridinyl]-methylidenohollongdione 9 emerged as the most active derivative as indicated by its GI₅₀ values in the micromolar range which, combined with its high selectivity index values, indicated its suitability for deeper biological investigation. The mechanisms involved in compound 9 antiproliferative activity, were investigated through in vitro (DAPI staining) and ex vivo (CAM assay) tests, which exhibited its apoptotic and antiangiogenic activities. In addition, compound 9 showed an overall inhibition of mitochondrial respiration. rtPCR analysis identified the more intimate activity at pro-survival/pro-apoptotic gene level. Collectively, the hollongdione derivative stand as a promising therapeutic option against melanoma and breast cancer provided that future in vivo analysis will certify its clinical efficacy.

New Investigations with Lupane Type A-Ring Azepane Triterpenoids for Antimycobacterial Drug Candidate Design

Twenty lupane type A-ring azepano-triterpenoids were synthesized from betulin and its related derivatives and their antitubercular activity against Mycobacterium tuberculosis, mono-resistant MTB strains, and nontuberculous strains Mycobacterium abscessus and Mycobacterium avium were investigated in the framework of AToMIc (Anti-mycobacterial Target or Mechanism Identification Contract) realized by the Division of Microbiology and Infectious Diseases, NIAID, National Institute of Health. Of all the tested triterpenoids, 17 compounds showed antitubercular activity and 6 compounds were highly active on the H37Rv wild strain (with MIC 0.5 µM for compound 7), out of which 4 derivatives also emerged as highly active compounds on the three mono-resistant MTB strains. Molecular docking corroborated with a machine learning drug-drug similarity algorithm revealed that azepano-triterpenoids have a rifampicin-like antitubercular activity, with compound 7 scoring the highest as a potential M. tuberculosis RNAP potential inhibitor. FIC testing demonstrated an additive effect of compound 7 when combined with rifampin, isoniazid and ethambutol. Most compounds were highly active against M. avium with compound 14 recording the same MIC value as the control rifampicin (0.0625 µM). The antitubercular ex vivo effectiveness of the tested compounds on THP-1 infected macrophages is correlated with their increased cell permeability. The tested triterpenoids also exhibit low cytotoxicity and do not induce antibacterial resistance in MTB strains.

Synthesis of erythrodiol C-ring derivatives and their activity against Chlamydia trachomatis

To develop new potential agents against Chlamydia trachomatis among oleanane type triterpenoids the synthesis, spectral and X-ray analysis as well as antimicrobial screening of C-12 oxygen and nitrogen derivatives of erythrodiol is presented. The reduction of methyl 3β-acetoxy-12-oxo-oleanoate with LiAlH₄ led to isomeric erythrodiol 12β- and 12α-hydroxy-derivatives, their stereochemistry with respect to the position of hydroxyl-group at C-12 was determined based on the multiplets splitting patterns, the magnitude of the spin-spin interaction, and NOESY interactions. Methyl 3β-acetoxy-12-oxo-oleanoate was transformed to 12E-hydroxyimino- and 12E-methoxyimino-derivatives by the interaction with NH₂OH∙HCl or CH₃ONH₂∙HCl, respectively. By Beckmann rearrangement with SOCl₂ in dioxane 12E-oxime was converted to C-lactame and its following reduction with LiAlH₄ in THF or dioxane led to erythrodiol C-azepanone or C-azepane derivatives. The structure 3-O,12-N-bis-acetyl-derivative of C-azepane-erythrodiol was confirmed by the single crystal X-ray analysis. Erythrodiol 12β-hydroxy- and C-azepane derivatives were found to be lead compounds with significant activity against C. trachomatis with MIC 1.56 and 3.125 μg/mL. Molecular docking was employed to suggest potential binding interaction, the tested compounds are likely to act as Cdu1 protein inhibitors while 12β-hydroxy-erythrodiol exhibited the highest affinity towards this respective target protein. These results indicated that C-ring oxygen and nitrogen erythrodiol derivatives might be considered for further research in the design of antibacterial agents against Chlamydia trachomatis.

3-Pyridinylidene Derivatives of Chemically Modified Lupane and Ursane Triterpenes as Promising Anticancer Agents by Targeting Apoptosis

Cancer persists as a global challenge due to the extent to which conventional anticancer therapies pose high risks counterbalanced with their therapeutic benefit. Naturally occurring substances stand as an important safer alternative source for anticancer drug development. In the current study, a series of modified lupane and ursane derivatives was subjected to in vitro screening on the NCI-60 cancer cell line panel. Compounds 6 and 7 have been identified as highly active with GI₅₀ values ranging from 0.03 µM to 5.9 µM (compound 6) and 0.18–1.53 µM (compound 7). Thus, these two compounds were further assessed in detail in order to identify a possible antiproliferative mechanism of action. DAPI (4′,6-diamidino-2-phenylindole) staining revealed that both compounds induced nuclei condensation and overall cell morphological changes consistent with apoptotic cell death. rtPCR analysis showed that both compounds induced upregulation of proapoptotic Bak and Bad genes while downregulating Bcl-XL and Bcl-2 antiapoptotic genes. Molecular docking analysis revealed that both compounds exhibited high scores for Bcl-XL inhibition, while compound 7 showed higher in silico Bcl-XL inhibition potential as compared to the native inhibitor ATB-737, suggesting that compounds may induce apoptotic cell death through targeted antiapoptotic protein inhibition, as well.

In Silico and In Vitro Evaluation of the Antimicrobial and Antioxidant Potential of Mentha × smithiana R. GRAHAM Essential Oil from Western Romania

This study was conducted to identify the volatile compounds of Mentha × smithiana essential oil (MSEO) and evaluate its antioxidant and antibacterial potential. The essential oil (EO) content was assessed by gas chromatography-mass spectrometry (GC-MS). Carvone (55.71%), limonene (18.83%), trans-carveol (3.54%), cis-carveol (2.72%), beta-bourbonene (1.94%), and caryophyllene oxide (1.59%) were the main identified compounds. The MSEO displayed broad-spectrum antibacterial effects and was also found to be the most effective antifungal agent against Candida albicans and Candida parapsilosis. The antioxidant activity of MSEO was tested against cold-pressed sunflower oil by peroxide, thiobarbituric acid, 1,1-diphenyl-2-picrylhydrazyl radical (DPPH), and β-carotene/linoleic acid bleaching methods. The EO showed strong antioxidant effects as reflected by IC50 values of 0.83 ± 0.01 mg/mL and relative antioxidative activity of 87.32 ± 0.03% in DPPH and β-carotene/linoleic acid bleaching assays, respectively. Moreover, in the first 8 days of the incubation period, the inhibition of primary and secondary oxidation compounds induced by the MSEO (0.3 mg/mL) was significantly stronger (p < 0.05) than that of butylated hydroxyanisole. In silico molecular docking studies were conducted to highlight the underlying antimicrobial mechanism as well as the in vitro antioxidant potential. Recorded data showed that the antimicrobial activity of MSEO compounds could be exerted through the D-Alanine-d-alanine ligase (DDl) inhibition and may be attributed to a cumulative effect. The most active compounds are minor components of the MSEO. Docking results also revealed that several mint EO components could exert their in vitro antioxidant activity by employing xanthine oxidase inhibition. Consequently, MSEO could be a new natural source of antioxidants and antiseptics, with potential applications in the food and pharmaceutical industries as an alternative to the utilization of synthetic additives.

Antibiotics: Conventional Therapy and Natural Compounds with Antibacterial Activity-A Pharmaco-Toxicological Screening

Antibiotics are considered as a cornerstone of modern medicine and their discovery offers the resolution to the infectious diseases problem. However, the excessive use of antibiotics worldwide has generated a critical public health issue and the bacterial resistance correlated with antibiotics inefficiency is still unsolved. Finding novel therapeutic approaches to overcome bacterial resistance is imperative, and natural compounds with antibacterial effects could be considered a promising option. The role played by antibiotics in tumorigenesis and their interrelation with the microbiota are still debatable and are far from being elucidated. Thus, the present manuscript offers a global perspective on antibiotics in terms of evolution from a historical perspective with an emphasis on the main classes of antibiotics and their adverse effects. It also highlights the connection between antibiotics and microbiota, focusing on the dual role played by antibiotics in tumorigenesis. In addition, using the natural compounds with antibacterial properties as potential alternatives for the classical antibiotic therapy is discussed.

Natural Compounds in Sex Hormone-Dependent Cancers: The Role of Triterpenes as Therapeutic Agents

Sex hormone-dependent cancers currently contribute to the high number of cancer-related deaths worldwide. The study and elucidation of the molecular mechanisms underlying the progression of these tumors was a double-edged sword, leading to the expansion and development of new treatment options, with the cost of triggering more aggressive, therapy resistant relapses. The interaction of androgen, estrogen and progesterone hormones with specific receptors (AR, ER, PR) has emerged as a key player in the development and progression of breast, ovarian, prostate and endometrium cancers. Sex hormone-dependent cancers share a common and rather unique carcinogenesis mechanism involving the active role of endogenous and exogenous sex hormones to maintain high mitotic rates and increased cell proliferation thus increasing the probability of aberrant gene occurrence and accumulation highly correlated with abnormal cell division and the occurrence of malignant phenotypes. Cancer related hormone therapy has evolved, currently being associated with the blockade of other signaling pathways often associated with carcinogenesis and tumor progression in cancers, with promising results. However, despite the established developments, there are still several shortcomings to be addressed. Triterpenes are natural occurring secondary metabolites biosynthesized by various pathways starting from squalene cyclization. Due to their versatile therapeutic potential, including the extensively researched antiproliferative effect, these compounds are most definitely a cornerstone in the research and development of new natural/semisynthetic anticancer therapies. The present work thoroughly describes the ongoing research related to the antitumor activity of triterpenes in sex hormone-dependent cancers. Also, the current review highlights both the biological activity of various triterpenoid compounds and their featured mechanisms of action correlated with important chemical structural features.

Tetracyclic and Pentacyclic Triterpenes with High Therapeutic Efficiency in Wound Healing Approaches

Wounds are among the most common skin conditions, displaying a large etiological diversity and being characterized by different degrees of severity. Wound healing is a complex process that involves multiple steps such as inflammation, proliferation and maturation and ends with scar formation. Since ancient times, a widely used option for treating skin wounds are plant- based treatments which currently have become the subject of modern pharmaceutical formulations. Triterpenes with tetracyclic and pentacyclic structure are extensively studied for their implication in wound healing as well as to determine their molecular mechanisms of action. The current review aims to summarize the main results of in vitro, in vivo and clinical studies conducted on lupane, ursane, oleanane, dammarane, lanostane and cycloartane type triterpenes as potential wound healing treatments.

Thermosensitive Betulinic Acid-Loaded Magnetoliposomes: A Promising Antitumor Potential for Highly Aggressive Human Breast Adenocarcinoma Cells Under Hyperthermic Conditions

PURPOSE

Breast cancer presents one of the highest rates of prevalence around the world. Despite this, the current breast cancer therapy is characterized by significant side effects and high risk of recurrence. The present work aimed to develop a new therapeutic strategy that may improve the current breast cancer therapy by developing a heat-sensitive liposomal nano-platform suitable to incorporate both anti-tumor betulinic acid (BA) compound and magnetic iron nanoparticles (MIONPs), in order to address both remote drug release and hyperthermia-inducing features. To address the above-mentioned biomedical purposes, the nanocarrier must possess specific features such as specific phase transition temperature, diameter below 200 nm, superparamagnetic properties and heating capacity. Moreover, the anti-tumor activity of the developed nanocarrier should significantly affect human breast adenocarcinoma cells.

METHODS

BA-loaded magnetoliposomes and corresponding controls (BA-free liposomes and liposomes containing no magnetic payload) were obtained through the thin-layer hydration method. The quality and stability of the multifunctional platforms were physico-chemically analysed by the means of RAMAN, scanning electron microscopy-EDAX, dynamic light scattering, zeta potential and DSC analysis. Besides this, the magnetic characterization of magnetoliposomes was performed in terms of superparamagnetic behaviour and heating capacity. The biological profile of the platforms and controls was screened through multiple in vitro methods, such as MTT, LDH and scratch assays, together with immunofluorescence staining. In addition, CAM assay was performed in order to assess a possible anti-angiogenic activity induced by the test samples.

RESULTS

The physico-chemical analysis revealed that BA-loaded magnetoliposomes present suitable characteristics for the purpose of this study, showing biocompatible phase transition temperature, a diameter of 198 nm, superparamagnetic features and heating capacity. In vitro results showed that hyperthermia induces enhanced anti-tumor activity when breast adenocarcinoma MDA-MB-231 cells were exposed to BA-loaded magnetoliposomes, while a low cytotoxic rate was exhibited by the non-tumorigenic breast epithelial MCF 10A cells. Moreover, the in ovo angiogenesis assay endorsed the efficacy of this multifunctional platform as a good strategy for breast cancer therapy, under hyperthermal conditions. Regarding the possible mechanism of action of this multifunctional nano-platform, the immunocytochemistry of the MCF7 and MDA-MB-231 breast carcinoma cells revealed a microtubule assembly modulatory activity, under hyperthermal conditions.

CONCLUSION

Collectively, these findings indicate that BA-loaded magnetoliposomes, under hyperthermal conditions, might serve as a promising strategy for breast adenocarcinoma treatment.

Antimycobacterial activity of azepanobetulin and its derivative: In vitro, in vivo, ADMET and docking studies

The antimycobacterial investigation of azepanobetulin and its amide derivative was performed. Both compounds showed increased in vitro antibacterial activity on the H37Rv MTB strain in aerobic and anaerobic conditions. Basing on differences between MIC and IC₅₀ values a predominant bactericidal effect for amide in contrast to azepanobetulin with a bacteriostatic antibacterial mechanism is defined. Both compounds showed a strong antibacterial effect against resistant MTB strains with amide derivative being slightly more active. Amide derivative also showed a higher antibacterial potency against non-tuberculous mycobacterial strains (M. avium, M. abscessus). Molecular docking studies showed that the inhibition of tuberculosinyl adenosine transferase (Rv3378c) could constitute an antimycobacterial mechanism of action for these triterpenic azepane derivatives. The pharmacokinetic profile was evaluated by ADMET studies and azepanobetulin showing the better results was evaluated by in vivo experiments. This compound has demonstrated a statistically significant antimycobacterial activity compared to control, but inferior to isoniazid. Our findings show that pentacyclic triterpene derivatives holding a seven-membered azepane A-ring are the promising template for the development of new agents with high antibacterial potential against M. tuberculosis H37Rv, non-tuberculous mycobacterial and drug- resistant strains.

A Study on the Behavior of a Polyurethane Drug Carrier in Various pH Media

Polyurethane nano- and micro-structures have been studied intensively in the last decade as drug delivery systems for various herbal extracts as well as pure active biological substances. Their biocompatibility, haemocompatibility, safe degradation, and low-cost production are just a few advantages of these materials that were already used in numerous medical applications (catheters, surgical drapes, wound dressing). The primary purposes of this study include obtaining empty polyurethane microstructures and the assessment of their modifications in media with different pH values. A mixture of two aliphatic diisocyanates and an aqueous phase based on a polyether were used during the synthesis process. The size, homogeneity, and surface charge were studied using a Cordouan Technol. Zetasizer, while the pH measurements were conducted with a portable pH Meter Checker®, Hanna Instruments. The results showed the obtaining of an almost homogeneous sample containing microstructures with sizes ranging between 139 and 151 nm, with a pH value of approximately 6.78 and a Zeta potential of 24.6. Expected decreases in microparticles’ sizes were observed in all types of media during a 15-days experiment, but the process was accelerated by a low pH when an increase of the Zeta potential value was noticed as well. Our data provide new information about the degradation process of the polyurethane microstructures on the one hand and the drug release rate of these materials when used as drug carriers, on the other hand.

SARS-CoV-2: Repurposed Drugs and Novel Therapeutic Approaches-Insights into Chemical Structure-Biological Activity and Toxicological Screening

SARS-CoV-2 (severe acute respiratory syndrome coronavirus 2) pandemic represents the primary public health concern nowadays, and great efforts are made worldwide for efficient management of this crisis. Considerable scientific progress was recorded regarding SARS-CoV-2 infection in terms of genomic structure, diagnostic tools, viral transmission, mechanism of viral infection, symptomatology, clinical impact, and complications, but these data evolve constantly. Up to date, neither an effective vaccine nor SARS-CoV-2 specific antiviral agents have been approved, but significant advances were enlisted in this direction by investigating repurposed approved drugs (ongoing clinical trials) or developing innovative antiviral drugs (preclinical and clinical studies). This review presents a thorough analysis of repurposed drug admitted for compassionate use from a chemical structure-biological activity perspective highlighting the ADME (absorption, distribution, metabolism, and excretion) properties and the toxicophore groups linked to potential adverse effects. A detailed pharmacological description of the novel potential anti-COVID-19 therapeutics was also included. In addition, a comprehensible overview of SARS-CoV-2 infection in terms of general description and structure, mechanism of viral infection, and clinical impact was portrayed.

Hydro-alcoholic Extracts of Roots and Sprouts of Armoracia rusticana: Assessment of Antioxidant and Cytotoxic Activity

Armoracia rusticana � horseradish is a well-known vegetable used from ancient times and consumed nowadays more for its taste than its pharmacological properties, even though it proved to be a good agent in fighting several health problems. This study focuses on a comparative assessment of several horseradish hydro-alcoholic extracts, obtained from roots and sprouts, respectively, mainly evaluating the antioxidant activity but also a potential cytotoxic effect. The DPPH evaluation revealed that horseradish extracts made from roots or sprouts exhibit a strong antioxidant activity compared to the ascorbic acid used as etalon. The in vitro evaluation established that a significant inhibitory effect on cell viability and morphology of MDA-MB-231 � breast adenocarcinoma cell line was displayed by the hydroalcoholic extracts in a dose-dependent manner.

Gold Nanoparticles as Targeted Delivery Systems and Theranostic Agents in Cancer Therapy

Cancer is still a leading cause of death worldwide, while most chemotherapies induce nonselective toxicity and severe systemic side effects. To address these problems, targeted nanoscience is an emerging field that promises to benefit cancer patients. Gold nanoparticles are nowadays in the spotlight due to their many well-established advantages. Gold nanoparticles are easily synthesizable in various shapes and sizes by a continuously developing set of means, including chemical, physical or eco-friendly biological methods. This review presents gold nanoparticles as versatile therapeutic agents playing many roles, such as targeted delivery systems (anticancer agents, nucleic acids, biological proteins, vaccines), theranostics and agents in photothermal therapy. They have also been outlined to bring great contributions in the bioimaging field such as radiotherapy, magnetic resonance angiography and photoacoustic imaging. Nevertheless, gold nanoparticles are therapeutic agents demonstrating its in vitro anti-angiogenic, anti-proliferative and pro-apoptotic effects on various cell lines, such as human cervix, human breast, human lung, human prostate and murine melanoma cancer cells. In vivo studies have pointed out data regarding the bioaccumulation and cytotoxicity of gold nanoparticles, but it has been emphasized that size, dose, surface charge, sex and especially administration routes are very important variables.

Cocrystal Formation of Betulinic Acid and Ascorbic Acid: Synthesis, Physico-Chemical Assessment, Antioxidant, and Antiproliferative Activity

Betulinic acid (BA) was demonstrated to be a very promising anticancer agent against various tumor cell lines such as breast, colon, lung, and brain. Despite its strong cytotoxic effect, betulinic acid exhibits low water solubility, feature that is reflected in its poor bioavailability. To overcome these drawbacks, numerous strategies were conducted to improve its physicochemical and pharmacokinetic profile, among which cocrystalization emerged as a promising approach. Thus, our work consisted in obtaining slowly grown cocrystals of BA and ascorbic acid (BA+VitC) in isopropyl alcohol obtained in a hydrothermal experiment. The newly formed cocrystals were characterized by physico-chemical methods such asSEM, DSC, XRPD, and FT-IR spectroscopy demonstrating BA+VitC cocrystal formation while their antioxidant activity revealed an additive antioxidant effect. To investigate the biological effect, BA+VitC cocrystals were tested on HaCat (immortalized human keratinocytes), B164A5 and B16F0 (murine melanoma), MCF7 and MDA-MB-231 (human breast cancer), and HeLa (cervical cancer) cell lines. Results of BA upon the tested tumor cell lines, after co-crystallization with vitamin C, indicated a superior cytotoxic effect with the preservation of a good selectivity index assumably due to an improved BA water solubility and consequently an optimized bioavailability.

In silico Evaluation of the Antiproliferative Mithocondrial Targeted Mechanism of Action of Some Pentacyclic Triterpene Derivatives

Mitochondria play an important role in regulating cell viability. Mitochondrial dysfunction has been associated with many known pathologies including cancer. Mitocans are a class of compounds that alter important mitochondrial functions in cancer cells thus inducing cellular death. New pentacyclic triterpene derivatives are constantly developed with the aim of obtaining highly active antiproliferative agents. In this study a set of previously synthesized rhodamine B triterpene conjugates, designed as mitocans, were in silico evaluated with the purpose of elucidating their targeted mithocondrial mechanism of action. Molecular docking revealed that the compounds would predominantly interact with proteins that are part of the mithocondrial electron transport chain (ETC), such as NAD(P)H-quinone oxidoreductase (NDH) and succinate dehydrogenase (SDH).

Betulin silver nanoparticles qualify as efficient antimelanoma agents in in vitro and in vivo studies

The current study was purported to assess the: (i) in vitro toxicity of betulin silver nanoparticles (AgNPs-B), bare and capped with polyethylene glycol (PEG), on two murine melanoma cell lines (B164A5 and B16Ova) and on healthy cell lines (keratinocytes and melanocytes), and (ii) in vivo antitumor efficacy of PEGylated AgNPs-B in an experimental melanoma model. Bare and PEG-capped AgNPs-B were synthesized by a chemical reduction method resulting in stable and non-aggregated spherical AgNPs-B and PEG-AgNPs-B, of narrow size distributions and mean hydrodynamic diameters of 25 nm and 75 nm, respectively. In vitro assessments were achieved by MTT and Annexin V-FITC assays and in vivo evaluation involved non-invasive techniques for the surveillance of the physiological skin parameters changes and histopathological examination of the harvested organs. The in vitro results revealed selective cytotoxicity against melanoma cells, at low doses that are nontoxic to normal cells; higher doses were associated with the loss of selectivity and toxicity for healthy cells. PEGylated formulation of betulin exerted a dose-dependent pro-apoptotic effect, more obvious in the case of B164A5 cells. Histopathological analysis suggested that PEGylated AgNPs-B developed relevant in vivo effects as antimelanoma agents by decreasing the tumor volume and inhibiting the development of secondary tumors.

Binding Affinity of 17-b-ethinylestradiol to Normal and Mutant Types of Estrogen Receptors An in silico evaluation

Estrogen receptors (ERs)are nuclear transcription factor receptorsthat play important roles in gene expression and cell cycle regulation. Because of their ligand-activated signaling implication in carcinogenesis,ERs are extensively researched as protein targets for anti-cancer drug discovery active in certain types of tumors. However, a major drawback is the emergence of wild type tumors withoverexpressed mutant variants of ER, which become resistant to estrogen inhibitor drugs. Herein we studied the binding mode and affinity of the semisynthetic estrogen agonist, 17-b-estradiol (E2) in normal and mutant variants of ERs, by means of molecular docking. Our results showed a small decrease in binding affinity, recorded in mutant variants of ERa and a change in the binding interactions formed when the compound wasdocked in an agonist-bound conformation of the ERa . Nevertheless we concluded that even if the binding affinity showed a small decrease in the case of mutant type receptors,E2 potency towards ER�won�t register a downward trend.

Design, Synthesis and Biological Activity Evaluation of S-Substituted 1H-5-Mercapto-1,2,4-Triazole Derivatives as Antiproliferative Agents in Colorectal Cancer

Colon cancer is a widespread pathology with complex biochemical etiology based on a significant number of intracellular signaling pathways that play important roles in carcinogenesis, tumor proliferation and metastasis. These pathways function due to the action of key enzymes that can be used as targets for new anticancer drug development. Herein we report the synthesis and biological antiproliferative evaluation of a series of novel S-substituted 1H-3-R-5-mercapto-1,2,4-triazoles, on a colorectal cancer cell line, HT-29. Synthesized compounds were designed by docking based virtual screening (DBVS) of a previous constructed compound library against protein targets, known for their important role in colorectal cancer signaling: MEK1, ERK2, PDK1, VEGFR2. Among all synthesized structures, TZ55.7, which was retained as a possible PDK1 (phospholipid-dependent kinase 1) inhibitor, exhibited the most significant cytotoxic activity against HT-29 tumor cell line. The same compound alongside other two, TZ53.7 and TZ3a.7, led to a significant cell cycle arrest in both sub G0/G1 and G0/G1 phase. This study provides future perspectives for the development of new agents containing the 1,2,4-mercapto triazole scaffold with antiproliferative activities in colorectal cancer.

The Cytotoxic Effects of Betulin-Conjugated Gold Nanoparticles as Stable Formulations in Normal and Melanoma Cells

Gold nanoparticles are currently investigated as theranostics tools in cancer therapy due to their proper biocompatibility and increased efficacy related to the ease to customize the surface properties and to conjugate other molecules. Betulin, [lup-20(29)-ene-3β, 28-diol], is a pentacyclic triterpene that has raised scientific interest due to its antiproliferative effect on several cancer types. Herein we described the synthesis of surface modified betulin-conjugated gold nanoparticles using a slightly modified Turkevich method. Transmission electron microscopy (TEM) imaging, dynamic light scattering (DLS), scanning electron microscopy (SEM) and energy-dispersive X-ray spectroscopy (EDX) were used for the characterization of obtained gold nanoparticles. Cytotoxic activity and apoptosis assessment were carried out using the MTT and Annexin V/PI apoptosis assays. The in vitro results showed that betulin coated gold nanoparticles presented a dose-dependent cytotoxic effect and induced apoptosis in all tested cell lines.

Stable PEG-coated silver nanoparticles - A comprehensive toxicological profile

The present study was purported to assess the toxicological profile of bare and polyethylene glycol (PEG) coated spherical silver nanoparticles (AgNPs) by means of in vitro (on human keratinocytes - HaCat cells) and in vivo non-invasive tests (after intraperitoneal - i.p. administration to mice). Bare and PEG-coated AgNPs were synthesized by applying Turkevich's method slightly modified. The physico-chemical characterization revealed the formation of stable, spherical AgNPs and PEG-AgNPs, with narrow size distributions and mean hydrodynamic sizes in the range of 19 nm and 50 nm, respectively. Toxicity data revealed a dose-dependent safe profile for low concentrations of test compounds (<10 μM) in terms of cell viability, whereas higher concentrations were associated with a high rate of cell mortality. In vivo acute/subacute toxicity data showed no denotive changes in mice health status after i.p. administration. Histological observations of internal organs and the biochemical parameters analyzed together with the other biological observations showed a low toxicity level with no major differences related to control, albeit at skin level a reduced number of mast cells was detected. All these observations provide strong support for the idea that coated silver nanoparticles could be applied as targeted nanocarriers for skin pathologies and diagnostic.

Total Polyphenol Content and Antiproliferative Activity of Green Tea Extracts Collected from Romanian Pharmaceuticals Market

Total polyphenol content and anti proliferative activity of five green tea extracts available on the Romanian pharmaceuticals market was analyzed. Results show dose-dependent anti proliferative activity of the selected samples against B164A5 mouse melanoma and A375 human melanoma cell lines. Sample 3, the richest sample in polyphenols showed the highest anti proliferative potential against the screened melanoma cell lines.

Synthesis, Characterization and Antiproliferative Activity Assessment of a Novel 1H-5-mercapto-1,2,4 Triazole Derivative

Angiogenesis plays an important function in tumor proliferation, one of the main angiogenic promoters being the vascular endothelial growth factor (VEGF) which activates specific receptors, particularly VEGFR-2. Thus, VEGFR-2 has become an essential therapeutic target in the development of new antitumor drugs. 1,2,4-triazoles show a wide range of biological activities, including antitumor effect, which was documented by numerous reports. In the current study the selection of 5-mercapto-1,2,4-triazole structure (1H-3-styryl-5-benzylidenehydrazino-carbonyl-methylsulfanil-1,2,4-triazole, Tz3a.7) was conducted based on molecular docking that emphasized it as suitable ligand for VEGFR-2 and EGFR1 receptors. Compound Tz3a.7 was synthesized and physicochemically and biologically evaluated thus revealing a moderate antiproliferative activity against breast cancer cell line MDA-MB-231.

Docking Study of 3-mercapto-1,2,4-triazole Derivatives as Inhibitors for VEGFR and EGFR

Computer-aided drug design plays an important role in modern day drug discovery, because it provides a more specific range for active compound chemical synthesis in detriment of the traditional ways of drug discovery. Relevant studies proved that the epidermal growth factor receptor (EGFR) and vascular endothelial growth factor receptor (VEGFR) are important targets for inhibition, in finding new molecules with potential anticancer activity. The aim of the present study was to create a compound library and submit this set of molecules to a docking-based virtual screening process. Molecular docking was carried out using OEDocking HYBRYD, a software with an improved scoring algorithm, which uses a ligand-based scoring function. The obtained results revealed some molecular structures that showed good predicted binding affinity towards their respective protein targets.

Design, synthesis and pharmaco-toxicological assessment of 5-mercapto-1,2,4-triazole derivatives with antibacterial and antiproliferative activity

The extensive biochemical research of multiple types of cancer has revealed important enzymatic signaling pathways responsible for tumor occurrence and progression, thus compelling the need for the discovery of new means with which to block these signaling cascades. The phosphoinositide 3-kinase/protein kinase B (PI3K/AKT) pathway, which plays an important role in maintaining relevant cellular functions, exhibits various alterations in common human cancers, thus representing a suitable target in cancer treatment. Molecules bearing the 1,2,4-triazole moiety are known to possess multiple biological activities, including anticancer activity. The current study used molecular docking in the design of 5-mercapto-1,2,4-triazole derivatives with antiproliferative activity targeting the PI3K/AKT pathway. Three structures emerged as the result of this method, which indicated for these a highly favorable accommodation within the active binding site of PI3K protein, thus acting as potential PI3K inhibitors, and hence interfering with the above-mentioned pathway. The molecules were synthesized and their chemical structure was confirmed. The antiproliferative activity of these compounds was tested on 4 cancer cell lines (A375, B164A5, MDA-MB-231 and A549) and on normal human keratinocytes (HaCaT) by in vitro alamarBlue assay. The 3 compounds revealed antitumor activity against the breast cancer cell line (MDA-MB-231) and reduced toxicity on the normal cell line. The antibacterial activity of the compounds was also tested in vitro on Gram-positive and Gram-negative bacterial strains, revealing moderate activity.

Improvement of ursolic and oleanolic acids' antitumor activity by complexation with hydrophilic cyclodextrins

Ursolic and oleanolic acids have been brought into the spotlight of research due to their chemopreventive, anti-inflammatory and immunomodulatory properties. The most important disadvantage of ursolic and oleanolic acids is their weak water solubility which limits their bioavailability. Pentacyclic triterpenes can form inclusion complexes with different types of cyclodextrins which provide the hydrophilic matrix requested for the molecular dispersion of drugs in order to become more water soluble. The aim of the current study is the complexation of ursolic and oleanolic acids with hydrophilic cyclodextrins in order to achieve an improvement of their pharmacological effect. After the virtual screening of the binding affinities between ursolic and oleanolic acids and various cyclodextrins, 2-hydroxypropyl-β-cyclodextrin and 2-hydroxypropil-γ-cyclodextrin were selected as host-molecules for the inclusion complexation. Using the scanning electron microscopy, differential scanning calorimetry and X-ray diffraction the formation of real inclusion complexes between ursolic and oleanolic acids and the two cyclodextrins was confirmed. The anti-proliferative potential of the complexes was tested in vitro on several melanoma cell lines, using the pure compounds as reference. The complexes exhibited higher in vitro anti-proliferative activity as compared to the pure compounds; this improvement was significant for ursolic acid complexes, the highest activity being reported for the 2-hydroxypropil-γ-cyclodextrin complex. Weaker results were recorded for the oleanolic acid complexes where 2-hydroxypropyl-β-cyclodextrin proved to be the most fitted inclusion partner. The entrapment of the two active compounds inside ramified hydrophilic cyclodextrins proved to be a suitable option to increase their anti-proliferative activity.

Nanocarriers as Tools in Delivering Active Compounds for Immune System Related Pathologies

BACKGROUND

Immune system related pathologies affect an increasing number of patients every year, having potentially lethal consequences and requiring expensive and difficult tolerated treatments. This area of pathologies offers an excellent potential for the development of innovative solutions such as nanoformulations; this review aims to describe the main categories of nanostructured drug delivery platforms that have been developed in order to achieve a more effective, low toxic treatment in autoimmune pathologies.

METHODS

We conducted a systematic search of peer-reviewed original studies focusing on nanoformulations suitable for use against autoimmune disorders. Each study was evaluated by at least two reviewers who applied inclusion and exclusion criteria in order to establish the quality of the research reported in the selected papers. The systematic screening of the literature also identified the most recent patents issued in the field of inflammatory/autoimmune diseases which were included in the current paper.

RESULTS

One hundred ninety-seven bibliographic titles were included in the review of which fifty-three recently published patents. Twenty-one papers were selected to define the interaction between nanoformulations and the immune system triggering either immunosuppression or immunostimulation. Thirty-seven papers outlined the characteristics of liposomal formulations that have been reported as treatment for several autoimmune diseases including multiple sclerosis. Twentythree articles provided data on the main lipid nanoparticles of the first and second generation which may include physiological lipids with low cytotoxicity. Gold nanoparticles were described by thirteen papers which highlighted the advantages of the new hybrid organic-inorganic nanoparticles vs. the classical ionic gold compounds. Polymeric nanoformulations were the subject of fifty-nine papers that described their preparation as well as various advantages in the treatment of inflammatory disorders; dendrimers and polymeric micelles were included in the study. Thirty-three studies were selected to outline the benefits provided by the use of cyclodextrins as carriers for active drugs. The review also identified the possibility of producing combined nanoformulations (e.g. polymer/cyclodextrin, liposome/polymer) thus achieving superior therapeutic results.

CONCLUSION

Nanoformulations offer multiple advantages over the classical pharmaceutical formulations, the main ones being the precise targeted therapy with small doses of active drugs, longer circulating time in the bloodstream, and high loading capacity for diagnostic and therapeutic molecules; moreover, the nanoparticles may be functionalized in order to act as nanotheranostics within the larger frame of personalized medicine.

Solid-State Characterization and Biological Activity of Betulonic Acid Derivatives

Betulonic acid belongs to the pentacyclic triterpenic derivative class and can be obtained through the selective oxidation of betulin. In this study we set obtaining several functionalized derivatives of this compound by its condensation with several amino compounds such as aminoguanidine, hydroxylamine, n-butylamine and thiosemicarbazide as our goal. The functionalization of the parent compound led to several molecules with antiproliferative potential, the most promising being 3-2-carbamothioylhydrazonolup-20(29)-en-28-oic acid.

Application of acrylic spacers for long bone defects after tumoral resections

INTRODUCTIONS

Tumoral resections pose serious challenges because sufficient removal has to be balanced against function preservation. A particular type of resection is encountered when the tumor is located in the diaphysis. It can lead to an important gap which cannot always amend to bone grafting in the same procedure.

PATIENTS AND METHODS

The aim of the paper is to evaluate the long term outcome of segmental bone loss in patients with malignant tumors removed from diaphyseal regions and treated by intramedullary nailing and polymethylmethacrylate spacer. The limb function was then evaluated using a range of motion by the Musculoskeletal Tumor Score (MSTS) and the perceived quality of life measured by the EORTC QLQ-C30.

RESULTS

There were no immediate postoperative local or systemic complications and no failures of the nail/cement construct. All cases were allowed immediate weight bearing (lower limb) and none were immobilized (upper limb). The average length of the bone defect was 9 (6-14) centimeters. The average follow-up was 2.5 (1-4) years.

CONCLUSIONS

Polymethylmethacrylate cement spacers, over intramedullary nailing, have statistically proved a feasible and inexpensive procedure with limited complications, low surgical stress and favorable functional outcomes. It can be a definitive therapy for advanced cases, as well as temporary solution which can be successfully converted to secondary bone grafting.

Bite force in subjects with complete dentition

Bite force is the condition, expression and measure of the masticatory function. The purpose of this study was to examine, by means of a newly constructed electronic gnathodynamometer, the values of maximal bite forces in subjects with complete dentition, the time in which they express 50% and 75% respectively of the total forces value, and the shape of the bite curve during testing. The obtained data was statistically analyzed with respect to gender and age. Analysis of the variance confirmed the finding that there was no statistically significant correlation between the values of forces and subjects' age, but there was a statistically significant difference between males and females in the values of the bite forces in the front segment, as well as between the values of the force on anterior and posterior teeth. The correlation between the time T1 posterior right and T1 posterior left, and between T1 and T2 for anterior teeth are statistically significant. Analysis of the bite curves suggests that males "bite" shorter than females with a sharper peak of the curve. Numerical values and bite curves should be a diagnostic factor in the further follow-up of subjects or in the choice of prosthodontic therapy.