In vitro comparison of new bisphosphonic acids and zoledronate effects on human gingival fibroblasts viability, inflammation and matrix turnover

Impact of Composition and Autoclave Sterilization on the Mechanical and Biological Properties of ECM-Mimicking Cryogels

Cryogels represent a valid strategy as scaffolds for tissue engineering. In order to adequately support adhesion and proliferation of anchorage-dependent cells, different polymers need to be combined within the same scaffold trying to mimic the complex features of a natural extracellular matrix (ECM). For this reason, in this work, gelatin (Gel) and chondroitin sulfate (CS), both functionalized with methacrylic groups to produce CSMA and GelMA derivatives, were selected to prepare cryogel networks. Both homopolymer and heteropolymer cryogels were produced, via radical crosslinking reactions carried out at -12 °C for 2 h. All the scaffolds were characterized for their mechanical, swelling and morphological properties, before and after autoclave sterilization. Moreover, they were evaluated for their biocompatibility and ability to support the adhesion of human gingival fibroblasts and tenocytes. GelMA-based homopolymer networks better withstood the autoclave sterilization process, compared to CSMA cryogels. Indeed, GelMA cryogels showed a decrease in stiffness of approximately 30%, whereas CSMA cryogels of approximately 80%. When GelMA and CSMA were blended in the same network, an intermediate outcome was observed. However, the hybrid scaffolds showed a general worsening of the biological performance. Indeed, despite their ability to withstand autoclave sterilization with limited modification of the mechanical and morphological properties, the hybrid cryogels exhibited poor cell adhesion and high LDH leakage. Therefore, not only do network components need to be properly selected, but also their combination and ability to withstand effective sterilization process should be carefully evaluated for the development of efficient scaffolds designed for tissue engineering purposes.

Snail Slime Extracted by a Cruelty Free Method Preserves Viability and Controls Inflammation Occurrence: A Focus on Fibroblasts

Snail slime (SS) is a viscous secretion obtained from different snail species. SS composition is variable according to factors such as the extraction method. Even if several papers have been published regarding this topic, the molecular mechanisms at the base of SS biological effects remain unexplored. Thus, the aim of this study is to evaluate the capability of SS, extracted with the cruelty-free Muller method, to promote viability and angiogenesis processes and, in parallel, to counteract inflammation occurrence on skin cell populations. SS was administered to keratinocytes, macrophages and fibroblasts, then cell viability, through 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT) test, cytotoxicity by lactate dehydrogenase (LDH) assay, morphology by haematoxylin-eosin staining, gene and protein expression through real-time polymerase chain reaction (PCR) and Western blot, cell cycle phases by flow cytometry, and collagen secretion using an enzyme-linked immunosorbent assay (ELISA) test, were measured. Our results evidence SS capability to promote fibroblast viability and to trigger recovery mechanisms by activating the Erk protein. Moreover, an appreciable anti-inflammatory effect due to the significant reduction in cyclooxygenase-2 expression, and a positive modulation of new blood vessel formation demonstrated by increased Angiopoietin 1 gene expression and a higher matrix deposition (evidenced by the augmented amount of released collagen I) can be identified. This evidence led us to assume that the Muller method extracted-SS represents a valuable and promising natural product suitable for cosmetic and skin care formulations.

Kinesin Eg5 Selective Inhibition by Newly Synthesized Molecules as an Alternative Approach to Counteract Breast Cancer Progression: An In Vitro Study

Breast cancer (BC) is one of the most diagnosed cancers in women. Recently, a promising target for BC treatment was found in kinesin Eg5, a mitotic motor protein that allows bipolar spindle formation and cell replication. Thus, the aim of this work was to evaluate the effects of novel thiadiazoline-based Eg5 inhibitors, analogs of K858, in an in vitro model of BC (MCF7 cell line). Compounds 2 and 41 were selected for their better profile as they reduce MCF7 viability at lower concentrations and with minimal effect on non-tumoral cells with respect to K858. Compounds 2 and 41 counteract MCF7 migration by negatively modulating the NF-kB/MMP-9 pathway. The expression of HIF-1α and VEGF appeared also reduced by 2 and 41 administration, thus preventing the recruitment of the molecular cascade involved in angiogenesis promotion. In addition, 2 provokes an increased caspase-3 activation thus triggering the MCF7 apoptotic event, while 41 and K858 seem to induce the necrosis axis, as disclosed by the increased expression of PARP. These results allow us to argue that 2 and 41 are able to simultaneously intervene on pivotal molecular signaling involved in breast cancer progression, leading to the assumption that Eg5 inhibition can represent a valid approach to counteract BC progression.

Influence of bisphosphonates on oral implantology: Sodium alendronate and zoledronic acid enhance the synthesis and activity of matrix metalloproteinases by gingival fibroblasts seeded on titanium

OBJECTIVE

This study aimed to assess the influence of the bisphosphonates zoledronic acid and sodium alendronate on MMP-2 and MMP-9 synthesis and activity by gingival fibroblasts seeded onto titanium substrate.

DESIGN

Titanium discs were placed in 24-well cell culture plates and gingival fibroblasts were seeded (1 × 10⁵ cells/discs) on them using Dulbecco's Modified Eagle's Medium (DMEM) + 10 % fetal bovine serum (FBS) for 24 h. After this period, a fresh serum-free DMEM containing zoledronic acid or sodium alendronate at 0.5 μM, 1 μM or 5 μM was applied on the cells for an additional of 24 h. Serum-free DMEM and tumor necrosis factor alpha (TNF-α) were used as negative and positive controls, respectively. MMP-2 and MMP-9 synthesis and activity were determined by ELISA (Enzyme-Linked Immunosorbent Assay) and conventional/in situ zymography. Quantitative data were analyzed by one-way ANOVA and Tukey's tests (α = 0.05). The in situ zymography data were qualitatively described.

RESULTS

Despite both bisphosphonates increased the MMPs synthesis, this effect was significant higher in zoledronic acid groups. MMPs activity resembled by gelatinolytic activity was also enhanced by sodium alendronate and zoledronic acid in a similar pattern.

CONCLUSIONS

Zoledronic acid and sodium alendronate increased in a dose-dependent manner MMP-2 and MMP-9 synthesis by gingival fibroblasts seeded on titanium. MMP-2 activity was up-regulated by zoledronic acid treatment.

Synthesis, Cytotoxicity and Anti-Proliferative Activity Against AGS Cells of New 3(2H)-Pyridazinone Derivatives Endowed with a Piperazinyl Linker

Novel twenty-three 3(2H)-pyridazinone derivatives were designed and synthesized based on the chemical requirements related to the anti-proliferative effects previously demonstrated within this scaffold. The introduction of a piperazinyl linker between the pyridazinone nucleus and the additional (un)substituted phenyl group led to some compounds endowed with a limited cytotoxicity against human gingival fibroblasts (HGFs) and good anti-proliferative effects against gastric adenocarcinoma cells (AGS) as evaluated by MTT and LDH assays, using doxorubicin as a positive control. Successive analyses revealed that the two most promising representative compounds (12 and 22) could exert their effects by inducing oxidative stress as demonstrated by the hydrogen peroxide release and the morphological changes (cell blebbing) revealed by light microscopy analysis after the haematoxylin-eosin staining. Moreover, to further assess the apoptotic process induced by compounds 12 and 22, Bax expression was measured by flow cytometry. These findings enlarged our knowledge of the structural requirements in this scaffold to display valuable biological effects against cancerous cell lines.

Biomarkers to predict the onset of biphosphonate-related osteonecrosis of the jaw: A systematic review

Background

The goal of this paper was to identify available biomarkers to predict the onset of biphosphonate-related osteonecrosis of the jaw (BRONJ).

Material and Methods

Case-control studies comparing the different concentrations of a series of molecules detected in serum and urine as matrices of BRONJ affected patients vs. non-affected were included. PRISMA guidelines for systematic reviews were used for the present paper. Two reviewers independently screened electronic databases (Medline, Web of science, and The Cochrane Library) and performed hand searches. Risk of bias assessment of selected studies was performed by the Newcastle-Ottawa Scale. This study is registered as PROSPERO CRD42017078149.

Results

From a total of 601 identified studies, 7 (4 articles with high methodological quality and 3 with medium) articles were included. They investigate 2623 patients, of whom 91 (3.47%) developed BRONJ. A total of 7 biomarkers were identified and classified into 3 groups: bone turnover, angiogenesis and endocrine markers. Conflicting results were found in relation to most biomarkers.

Conclusions

The present review suggests that no useful markers are currently available to evaluate BRONJ risk. Nevertheless, the present paper indicates that a paradigm shift from bone turnover biomarkers to angiogenesis and endocrine markers could shed light on this search.

Key words:Biphosphonate, jaw, osteonecrosis, osteoporosis.

Bisphosfonate matrix metalloproteinase inhibitors for the treatment of periodontitis: An in vitro study

Periodontitis is an inflammatory disease caused by anaerobic bacteria, including Porphyromonas gingivalis. Lipopolysaccharide (LPS)‑stimulated persistent inflammation is responsible for an increase in matrix metalloproteinase (MMP) expression, resulting in periodontal tissue destruction. The aim of the present study was to investigate synthesized bisphosphonic MMP inhibitors, in an in vitro model consisting of human gingival fibroblasts exposed to LPS, and to compare the biological responses to those induced by zoledronate (ZA), a commercial bisphosphonate. MTT and lactate dehydrogenase (LDH) assays were used to measure cell viability and cytotoxicity, respectively. ELISA was performed to evaluate prostaglandin E2 (PGE2), interleukin (IL)6 and collagen secretion, while western blotting was used to analyze MMP expression. No effect on viability and low cytotoxicity were observed following treatment with bisphosphonate compounds. In the present study, treatment with compound 1 did not increase the release of PGE2 and IL6. Increased levels of collagen I secretion were reported when compound 3 and ZA were administered. An increase of MMP8 was observed following ZA treatment, while a decrease of MMP9 and MMP14 following treatment with compounds 1, 2 and ZA were reported. The performance of compound 1 was optimal in terms of cell viability. Compound 1 also did not induce inflammation, and had the ability to counteract LPS‑induced increases in MMP expression. These data suggested that compound 1 was the most suitable treatment to progress to an in vivo animal study, with the aim to confirm its use for the treatment of periodontitis.