Generation of Pearl/Calcium Phosphate Composite Particles and Their Integration into Porous Chitosan Scaffolds for Bone Regeneration

Bone tissue engineering using osteoconductive scaffolds holds promise for regeneration, with pearl powder gaining interest for its bioactive qualities. This study used freeze drying to create chitosan (CS) scaffolds with pearl/calcium phosphate (p/CaP) powders, mimicking bone tissue structurally and compositionally. Characterization included scanning electron microscopy (SEM) and mechanical testing. X-ray diffraction (XRD) Fourier-transform infrared–photoacoustic photo-acoustic sampling (FTIR−PAS), and FTIR- attenuated total reflectance (FTIR-ATR) were used to characterize p/CaP. In vitro tests covered degradation, cell activity, and SEM analysis. The scaffolds showed notable compressive strength and modulus enhancements with increasing p/CaP content. Porosity, ranging from 60% to 90%, decreased significantly at higher pearl/CaP ratios. Optimal cell proliferation and differentiation were observed with scaffolds containing up to 30 wt.% p/CaP, with 30 wt.% pearl powder and 30 wt.% p/CaP yielding the best results. In conclusion, pearl/calcium phosphate chitosan (p/CaP_CS) composite scaffolds emerged as promising biomaterials for bone tissue engineering, combining structural mimicry and favourable biological responses

Evaluation of the Effect of Nano and Micro Hydroxyapatite Particles on the Impact Strength of Acrylic Resin: In Vitro Study

Poly (methylmethacrylate) is considered the basis material for a denture base. However, such substance has some drawbacks such as poor impact resistance, which is thought to be the primary cause of fracture of denture base resins. The purpose of the study was to determine how Nano and Micro hydroxyapatite particles affected the impact strength of acrylic resin. Thirty specimens were constructed of heat-cured acrylic resin and were divided into three groups: Ten specimens for the control, 10 for 1%nano hydroxyapatite, and 10 for micro hydroxyapatite. Acrylic samples were subjected to an impact strength test via a Charpy-type. Data were then analysed using SPSS v20. The ANOVA test was used for comparison among the groups. Highly statistically significant differences among all studied groups (P-value <0.0001). Both 5% Micro hydroxyapatite and 1% Nano hydroxyapatite had a higher mean value than the control. Incorporating Nano and Micro hydroxyapatite into PMMA improved the impact strength of acrylic resins

Synthesis of cerium, zirconium, and copper doped zinc oxide nanoparticles as potential biomaterials for tissue engineering applications

A novel eco-friendly high throughput continuous hydrothermal flow system was used to synthesise phase pure ZnO and doped ZnO in order to explore their properties for tissue engineering applications. Cerium, zirconium, and copper were introduced as dopants during flow synthesis of ZnO nanoparticles, Zirconium doped ZnO were successfully synthesised, however secondary phases of CeO and CuO were detected in X-ray diffraction (XRD). The nanoparticles were characterised using X-ray diffraction, Brunauer-Emmett-Teller (BET), Dynamic Light scattering Measurements, Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Fourier transform infrared spectroscopy (FT-IR) and RAMAN spectroscopy was used to evaluate physical, chemical, and structural properties. The change in BET surface area was also significant, the surface area increased from 11.35 (ZnO_2) to 26.18 (ZrZnO_5). However. In case of CeZnO_5 and CuZnO_5 was not significant 13.68 (CeZnO_5) and 12.16 (CuZnO_5) respectively. Cell metabolic activity analysis using osteoblast-like cells (MG63) and human embryonic derived mesenchymal stem cells (hES-MP) demonstrated that doped ZnO nanoparticles supported higher cell metabolic activity compared to cells grown in standard media with no nanoparticles added, or pure zinc oxide nanoparticles. The ZrZnO_5 demonstrated the highest cell metabolic activity and non-cytotoxicity over the duration of 28 days as compared to un doped or Ce or Cu incorporated nanoparticles. The current data suggests that Zirconium doping positively enhances the properties of ZnO nanoparticles by increasing the surface area and cell proliferation. Therefore, are potential additives within biomaterials or for tissue engineering applications

Global serum profiling: an opportunity for earlier cancer detection

The advances in cancer research achieved in the last 50 years have been remarkable and have provided a deeper knowledge of this disease in many of its conceptual and biochemical aspects. From viewing a tumor as a ‘simple’ aggregate of mutant cells and focusing on detecting key cell changes leading to the tumorigenesis, the understanding of cancer has broadened to consider it as a complex organ interacting with its close and far surroundings through tumor and non-tumor cells, metabolic mechanisms, and immune processes. Metabolism and the immune system have been linked to tumorigenesis and malignancy progression along with cancer-specific genetic mutations. However, most technologies developed to overcome the barriers to earlier detection are focused solely on genetic information. The concept of cancer as a complex organ has led to research on other analytical techniques, with the quest of finding a more sensitive and cost-effective comprehensive approach. Furthermore, artificial intelligence has gained broader consensus in the oncology community as a powerful tool with the potential to revolutionize cancer diagnosis for physicians. We herein explore the relevance of the concept of cancer as a complex organ interacting with the bodily surroundings, and focus on promising emerging technologies seeking to diagnose cancer earlier, such as liquid biopsies. We highlight the importance of a comprehensive approach to encompass all the tumor and non-tumor derived information salient to earlier cancer detection

Dietary flavonoids inhibit the anticancer effects of the proteasome inhibitor bortezomib

Dietary flavonolds have many health-promoting actions, including anticancer activity via proteasome inhibition. Bortezomib is a dipeptide boronate proteasome inhibitor that has activity in the treatment of multiple myeloma but Is not effective In chronic lymphocytic leukemia (CLL). Although CLL cells are sensitive In vitro to bortezomlb-induced apoptosis when cultured in medium, the killing activity was blocked when cultured In 50% fresh autologous plasma. Dietary flavonoids, quercetin and myrocetin, which are abundant In plasma, inhibited bortezomib-induced apoptosis of primary CLL and malignant B-cell lines in a dose-dependent manner. This inhibitory effect was associated with chemical reactions between quercetin and the boronic acid group, -RB(OH) 2 , in bortezomib. The addition of boric acid diminished the inhibitory effect of both quercetin and plasma on bortezomib-induced apoptosis. The protective effect was also reduced when myeloma cell lines, but not B-cell lines, were preincubated with quercetin, indicating a direct effect of quercetin on myeloma cells. At high doses, quercetin itself induced tumor cell death. These data indicate that dietary flavonoids limit the efficacy of bortezomib, whereas supplemental inorganic boric acid is able to reverse this. The complex interactions between quercetin, tumor cells, and bortezomib mean caution Is required when giving dietary advice to patients. © 2008 by The American Society of Hematology

Study of the Structure of Hyperbranched Polyglycerol Coatings and Their Antibiofouling and Antithrombotic Applications

While blood‐contacting materials are widely deployed in medicine in vascular stents, catheters, and cannulas, devices fail in situ because of thrombosis and restenosis. Furthermore, microbial attachment and biofilm formation is not an uncommon problem for medical devices. Even incremental improvements in hemocompatible materials can provide significant benefits for patients in terms of safety and patency as well as substantial cost savings. Herein, a novel but simple strategy is described for coating a range of medical materials, that can be applied to objects of complex geometry, involving plasma‐grafting of an ultrathin hyperbranched polyglycerol coating (HPG). Plasma activation creates highly reactive surface oxygen moieties that readily react with glycidol. Irrespective of the substrate, coatings are uniform and pinhole free, comprising O─C─O repeats, with HPG chains packing in a fashion that holds reversibly binding proteins at the coating surface. In vitro assays with planar test samples show that HPG prevents platelet adhesion and activation, as well as reducing (>3 log) bacterial attachment and preventing biofilm formation. Ex vivo and preclinical studies show that HPG‐coated nitinol stents do not elicit thrombosis or restenosis, nor complement or neutrophil activation. Subcutaneous implantation of HPG coated disks under the skin of mice shows no evidence of toxicity nor inflammation

In vitro degradation, swelling, and bioactivity performances of in situ forming injectable chitosan‐matrixed hydrogels for bone regeneration and drug delivery

Injectable, tissue mimetic, bioactive, and biodegradable hydrogels offer less invasive regeneration and repair of tissues. The monitoring swelling and in vitro degradation capacities of hydrogels are highly important for drug delivery and tissue regeneration processes. Bioactivity of bone tissue engineered constructs in terms of mineralized apatite formation capacity is also pivotal. We have previously reported in situ forming chitosan‐based injectable hydrogels integrated with hydroxyapatite and heparin for bone regeneration, promoting angiogenesis. These hydrogels were functionalized by glycerol and pH to improve their mechano‐structural properties. In the present study, functionalized hybrid hydrogels were investigated for their swelling, in vitro degradation, and bioactivity performances. Hydrogels have degraded gradually in phosphate‐buffered saline (PBS) with and without lysozyme enzyme. The percentage weight loss of hydrogels and their morphological and chemical properties, and pH of media were analyzed. The swelling ratio of hydrogels (55%–68%(wt), 6 h of equilibrium) indicated a high degree of cross‐linking, can be suitable for controlled drug release. Hydrogels have gradually degraded reaching to 60%–70% (wt%) in 42 days in the presence and absence of lysozyme, respectively. Simulated body fluid (SBF)‐treated hydrogels containing hydroxyapatite‐induced needle‐like carbonated‐apatite mineralization was further enhanced by heparin content significantly

OGC P44 Biospectrometry as a non invasive tool in the diagnosis of oesophageal cancer

Background Oesophageal adenocarcinoma (OAC) typically presents at an advanced stage with resultant poor survival rates. The 2022 oesophago-gastric (OG) audit suggests only 35.9% of patients diagnosed with OG cancer were treated with curative intent. Raman spectroscopy of serum is a non-invasive and rapid diagnostic technique which has proved promising in cancer diagnostics. A proof-of-concept study of 124 samples undertaken by our team to determine the accuracy of Raman spectral discrimination in detecting oesophageal transformation of Barrett’s to adenocarcinoma revealed sensitivity and specificity of over 95% when using serum to diagnose OAC. Methods Our research group has conducted a further study to validate the aforementioned findings by re-analysing 60 samples from the proof of concept study in a separate laboratory. Chemometric techniques, coupled with principal component analysis, were employed to identify discriminant spectral peaks. Subsequently, a prediction model was developed using a linear discriminant analysis algorithm to accurately classify serum samples from cancer patients. Results Spectral peaks representing methylene deformation at 1450 cm-1 and C-O stretch of ribose at 1012 cm-1 were identified as discriminant spectral peaks in identifying OAC in both analyses, inferring that these results are reproducible. A specificity and sensitivity of 72% and 71% respectively was calculated from chemometric spectral analysis. Conclusions We conclude that Raman spectroscopy has potential applications as a non-invasive screening tool for patients with suspected OAC

Characterisation of structural changes in collagen with Raman spectroscopy

Raman spectroscopy can detect conformational changes in collagen structures and these findings are reviewed in this article. More specifically, some progressive diseases are mainly caused by alterations of collagen molecules but what is occurring at the biochemical level of this complex molecule usually remains unclear. While it may be true that a number of analytical techniques can analyze collagen, most of them have a series of limitations that limit their applicability to a wide range of samples. To understand in more detail the progression of a disease due to changes in the collagen structure, a technique that can detect subtle alterations at the biochemical level is needed. Raman spectroscopy is a label-free and noninvasive technique that can easily pick up on any conformational changes reflected primarily at the lipids, amides and proline and hydroxyproline regions. This review is the first compilation of studies of conformational changes in collagen molecules, providing help to understand changes in collagen biochemistry that can be of relevance to the human wound healing, ageing and pathologies

Nanomechanical behavior of polystyrene/graphene oxide nanocomposites

The in-situ investigation of the nanomechanical features of the polymer graphene nanocomposites has become a challenging and an indispensable task to achieve the required application. Graphene oxide (GO) nanocomposites were prepared at 1.0% weight fraction of GO to reinforce polystyrene (PS) using solution blending approach. The morphology of the resulting nanocomposites was characterized by optical, scanning electron, transmission electron, atomic force, and scattering scanning near-field optical microscopies. These showed a uniform dispersion of graphene oxide nano-sheets in the PS matrix. By adopting Derjaguin–Muller–Toporov (DMT) formula, the nanomechanical properties for the cryogenically fractured surface of the composites were characterized using the traditional atomic force microscopy (AFM), peak-force quantitative nanomechanical mapping (QNM), and tip-force mode functioned with scattering scanning near–field optical microscopy (s-SNOM). Young’s modulus of the PS matrix varied around (1–2) GPa as shown by QNM and s-SNOM similar to what was reported in the literature. However, while putative GO nano-sheets were measured to have a higher elastic modulus than the surrounding matrix in Peak-Force QNM experiments, they were significantly below literature values. By using Tip-Force mode related to s-SNOM, the expected values of Young’s modulus for GO were recovered