Pharmacologically Induced Accommodation Palsy and the Bioelectrical Activity of the Muscular System: A Preliminary Investigation.

The aim of this study was to pharmacologically induce accommodative paralysis and evaluate its effects on the bioelectrical activity of the muscular system. The study included two participant groups: those with myopia and those with normal vision (emmetropes). Electromyographic assessments were performed using the Noraxon Ultium DTS 8-K MR 3 myo Muscle Master Edition system. The muscles analyzed in this study were the temporalis, masseter, sternocleidomastoid, trapezius, abdominal muscles, biceps brachii, and the external oblique muscles of the abdomen. It is important to acknowledge that, based on the current findings, it cannot be definitively stated that the observed effects have clinical significance, and additional studies are encouraged.

Infection with the multidrug-resistant Klebsiella pneumoniae New Delhi metallo-B-lactamase strain in patients with COVID-19: Nec Hercules contra plures?

Background: During the coronavirus disease 2019 (COVID-19) pandemic, in patients treated for SARS-CoV-2 infection, infections with the Klebsiella pneumoniae bacteria producing New Delhi metallo-B-lactamase (NDM) carbapenemase in the USA, Brazil, Mexico, and Italy were observed, especially in intensive care units (ICUs). This study aimed to assess the impact of Klebsiella pneumoniae NDM infection and other bacterial infections on mortality in patients treated in ICUs due to COVID-19. Methods: The 160 patients who qualified for the study were hospitalized in ICUs due to COVID-19. Three groups were distinguished: patients with COVID-19 infection only (N = 72), patients with COVID-19 infection and infection caused by Klebsiella pneumoniae NDM (N = 30), and patients with COVID-19 infection and infection of bacterial etiology other than Klebsiella pneumoniae NDM (N = 58). Mortality in the groups and chosen demographic data; biochemical parameters analyzed on days 1, 3, 5, and 7; comorbidities; and ICU scores were analyzed. Results: Bacterial infection, including with Klebsiella pneumoniae NDM type, did not elevate mortality rates. In the group of patients who survived the acute phase of COVID-19 the prolonged survival time was demonstrated: the median overall survival time was 13 days in the NDM bacterial infection group, 14 days in the other bacterial infection group, and 7 days in the COVID-19 only group. Comparing the COVID-19 with NDM infection and COVID-19 only groups, the adjusted model estimated a statistically significant hazard ratio of 0.28 (p = 0.002). Multivariate analysis revealed that age, APACHE II score, and CRP were predictors of mortality in all the patient groups. Conclusion: In patients treated for SARS-CoV-2 infection acquiring a bacterial infection due to prolonged hospitalization associated with the treatment of COVID-19 did not elevate mortality rates. The data suggests that in severe COVID-19 patients who survived beyond the first week of hospitalization, bacterial infections, particularly Klebsiella pneumoniae NDM, do not significantly impact mortality. Multivariate analysis revealed that age, APACHE II score, and CRP were predictors of mortality in all the patient groups.

Influence of Hybrid Surface Modification on Biocompatibility and Physicochemical Properties of Ti-6Al-4V ELI Titanium.

Titanium-based materials are the most widely used materials in biomedical applications. However, according to literature findings, the degradation products of titanium have been associated with potential allergic reactions, inflammation, and bone resorption. The corrosion process of Ti-6Al-4V in the human body environment may be exacerbated by factors such as reduced pH levels and elevated concentrations of chloride compounds. Coatings made of biopolymers are gaining attention as they offer numerous advantages for enhancing implant functionality, including improved biocompatibility, bioactivity, wettability, drug release, and antibacterial activity. This study analyzes the physicochemical and electrochemical behavior of the Ti-6Al-4V ELI alloy subjected to PCL and PCL/TiO2 deposition by the electrospinning method. To characterize the polymer-based layer, tests of chemical and phase composition, as well as surface morphology investigations, were performed. Wetting angle tests were conducted as part of assessing the physicochemical properties. The samples were subjected to corrosion behavior analysis, which included open circuit potential measurements, potentiodynamic tests, and the electrochemical impedance spectroscopy method. Additionally, the quantification of released ions post the potentiodynamic test was carried out using the inductively coupled plasma atomic emission spectrometry (ICP-AES) method. Cytotoxicity tests were also performed. It was found that surface modification by depositing a polymer-based layer on the titanium substrate material using the electrospinning method provides improved corrosion behavior, and the samples exhibit non-toxic properties.

How to Defeat Multidrug-Resistant Bacteria in Intensive Care Units. A Lesson from the COVID-19 Pandemic. Prevention, Reservoirs, and Implications for Clinical Practice.

Background: Intensive care unit (ICU) patients are at high risk of infection due to multiple invasive procedures, malnutrition, or immunosuppression. The rapid increase in infections with multidrug-resistant organisms (MDRO) during the COVID-19 pandemic caused a dilemma, as the rules of the sanitary regime in ICU rooms were strictly adhered to in the prevailing epidemiological situation. The combat to reduce the number of infections and pathogen transmission became a priority for ICU staff. This study aimed to assess whether eliminating environmental reservoirs and implementing improved procedures for patient care and decontamination and washing equipment in the ICU reduced the incidence of infections caused by MDR strains. Material and methods: The study retrospectively analyzed data in the ICU during the COVID-19 pandemic. The samples were collected based on microbiological culture and medical records in the newly opened ICU (10 stations) and hospital wards where COVID-19 patients were hospitalized. Environmental inoculations were performed during the COVID-19 pandemic every 4-6 weeks unless an increase in the incidence of infections caused by MDR strains was observed. Through microbiological analysis, environmental reservoirs of MDR pathogens were identified. The observation time was divided into two periods, before and after the revised procedures. The relationship between isolated strains of Klebsiella pneumoniae NDM from patients and potential reservoirs within the ICU using ERIC-PCR and dice methods was analyzed. Results: An increased frequency of infections and colonization caused by MDRO was observed compared to the preceding years. A total of 23,167 microbiological tests and 6,985 screening tests for CPE and MRSA bacilli were collected. The pathogen spread was analyzed, and the findings indicated procedural errors. Assuming that the transmission of infections through the staff hands was significantly limited by the restrictive use of personal protective equipment, the search for a reservoir of microorganisms in the environment began. MDR strains were grown from the inoculations collected from the hand-wash basins in the wards and from inside the air conditioner on the ceiling outside the patient rooms. New types of decontamination mats were used in high-risk areas with a disinfectant based on Glucoprotamine. Active chlorine-containing substances were widely used to clean and disinfect surfaces. Conclusions: Infections with MDR strains pose a challenge for health care. Identification of bacterial reservoirs and comprehensive nursing care significantly reduce the number of nosocomial infections.

Myopia & painful muscle form of temporomandibular disorders: connections between vision, masticatory and cervical muscles activity and sensitivity and sleep quality.

The main aim of this study is to evaluate the effects of painful muscle form of temporomandibular disorders and myopia on the connections between the visual organ, the bioelectrical activity and sensitivity of the masticatory and cervical muscles, and sleep quality. Subjects were divided into 4 groups (Myopia & TMDs, Myopia (Without TMDs), Emmetropic & TMDs and Emmetropic (Without TMDs)). The study was conducted in the following order of assessment: examination for temporomandibular disorders, assessment of the muscle activity by electromyograph, pressure pain thresholds examination, ophthalmic examination and completion of the Pittsburgh Sleep Quality Index. It was observed that the Myopia & TMDs group had higher muscle tenderness, higher resting and lower functional muscle bioelectrical activity. The visual organ is clinical related to the masticatory and cervical muscles. TMDs and myopia alter masticatory and cervical muscle activity. The thickness of the choroid in people with myopia is related to muscle tenderness. TMDs and myopia impair sleep quality. It is recommended to determine the number of people with refractive error and its magnitude in the sEMG study in order to be able to replicate the research methodology.

Between-Sex Differences in Risk Factors for Cardiovascular Disease among Patients with Myocardial Infarction-A Systematic Review.

Between-sex differences in the presentation, risk factors, management, and outcomes of acute myocardial infarction (MI) are well documented. However, as such differences are highly sensitive to cultural and social changes, there is a need to continuously re-evaluate the evidence. The present contemporary systematic review assesses the baseline characteristics of men and women presenting to secondary, tertiary, and quaternary centres with acute myocardial infarction (MI). Over 1.4 million participants from 18 studies, including primary prospective, cross sectional and retrospective observational studies, as well as secondary analysis of registry data are included in the study. The study showed that women were more likely than men to have a previous diagnosis of diabetes, hypertension, cerebrovascular disease, and heart failure. They also had lower odds of presenting with previous ischaemic heart disease and angina, dyslipidaemia, or a smoking history. Further work is necessary to understand the reasons for these differences, and the role that gender-specific risk factors may have in this context. Moreover, how these between-gender differences are implicated in management and outcomes also requires further work.

Genome editing in the mouse brain with minimally immunogenic Cas9 RNPs.

Transient delivery of CRISPR-Cas9 ribonucleoproteins (RNPs) into the central nervous system (CNS) for therapeutic genome editing could avoid limitations of viral vector-based delivery including cargo capacity, immunogenicity, and cost. Here, we tested the ability of cell-penetrant Cas9 RNPs to edit the mouse striatum when introduced using a convection-enhanced delivery system. These transient Cas9 RNPs showed comparable editing of neurons and reduced adaptive immune responses relative to one formulation of Cas9 delivered using AAV serotype 9. The production of ultra-low endotoxin Cas9 protein manufactured at scale further improved innate immunity. We conclude that injection-based delivery of minimally immunogenic CRISPR genome editing RNPs into the CNS provides a valuable alternative to virus-mediated genome editing.

Study protocol: Accommodative effects on the musculoskeletal system.

Accommodation is a phenomenon of the eyeball, which consists of adapting to view objects at different distances. The main aim of this study is to evaluate the effect of accommodations on the musculoskeletal system in myopic and emmetropic subjects. To date, the effect of accommodative paralysis on the musculoskeletal system has not been studied. The research hypothesis based on the current research reports is that accommodation affects the musculoskeletal system in myopic and emmetropic subjects. A smaller aim of the study is to evaluate the effect of unilateral accommodative palsy on the musculoskeletal system in myopic and emmetropic subjects. According to the authors of the previous reports, unilateral accommodative palsy will affect increased musculoskeletal asymmetry in myopic and emmetropic subjects. The surface electromyography (sEMG) of the musculoskeletal system will be performed by using the Noraxon Ultium DTS 8-K MR 3 myo Muscle Master Edition. Cycloftyal (10 mg/ml, eye drops, solution) will be used to paralyze accommodation. After the paralysis of unilateral accommodation, the test will be repeated. Both-sided accommodation will be paralyzed next, and the test will be repeated. The study may provide insight into the effects of accommodation on the musculoskeletal system, and it may also help in understanding the connections between these systems.

Effect of Selected Crosslinking and Stabilization Methods on the Properties of Porous Chitosan Composites Dedicated for Medical Applications.

Chitosan is one of the most commonly employed natural polymers for biomedical applications. However, in order to obtain stable chitosan biomaterials with appropriate strength properties, it is necessary to subject it to crosslinking or stabilization. Composites based on chitosan and bioglass were prepared using the lyophilization method. In the experimental design, six different methods were used to obtain stable, porous chitosan/bioglass biocomposite materials. This study compared the crosslinking/stabilization of chitosan/bioglass composites with ethanol, thermal dehydration, sodium tripolyphosphate, vanillin, genipin, and sodium ß-glycerophosphate. The physicochemical, mechanical, and biological properties of the obtained materials were compared. The results showed that all the selected crosslinking methods allow the production of stable, non-cytotoxic porous composites of chitosan/bioglass. The composite with genipin stood out with the best of the compared properties, taking into account biological and mechanical characteristics. The composite stabilized with ethanol is distinct in terms of its thermal properties and swelling stability, and it also promotes cell proliferation. Regarding the specific surface area, the highest value exposes the composite stabilized by the thermal dehydration method.

High Myopia and Thickness of Extraocular and Masticatory Muscles-7T MRI, Preliminary Study.

(1) Background: Myopia is one of the most common refractive errors in the world. The aim of this study was to evaluate the transverse dimensions of selected masticatory muscles (temporalis muscle and masseter muscle) versus the transverse dimensions of selected extraocular muscles (superior rectus, inferior rectus, medial rectus and lateral rectus) in emmetropic and high myopic subjects. (2) Methods: Twenty-seven individuals were included in the analysis, resulting in 24 eyeballs of patients with high myopia and 30 eyeballs of emmetropic subjects. A 7 Tesla resonance was used to analyze the described muscles. (3) Results: Statistical analysis showed differences in all analyzed extraocular muscles and all analyzed masticatory muscles between emmetropic subjects and high myopic subjects. In the high myopic subject group, statistical analysis showed four correlations. The three negative correlations were between the lateral rectus muscle and an axial length eyeball, refractive error and an axial length eyeball, and the inferior rectus muscle and visual acuity. The positive correlation was between the lateral rectus muscle and the medial rectus muscle. (4) Conclusions: The high myopic subjects are characterized by a larger cross-sectional area of extraocular muscles and masticatory muscles compared to the emmetropic subjects. Correlations were observed between the thickness of the extraocular muscles and the masticatory muscles. The lateral rectus muscle was related to the length of the eyeball. The phenomenon requires further study.

Correlation between refractive error, muscle thickness, and bioelectrical activity of selected masticatory muscles.

OBJECTIVE: The aim of this study was to analyze the correlation between the refractive error, muscle thickness, and the bioelectrical activity of selected masticatory and neck muscles in subjects with myopia. METHODS: For bioelectrical activity analysis within the masticatory muscles, an 8-channel BioEMG III electromyograph was used. An M-Turbo ultrasound machine was used to analyze the masticatory and neck muscle thickness. RESULTS: Statistical analysis showed significant positive correlations between masseter muscle thickness at rest on the right side. Statistical analysis showed negative correlations between the digastric muscle and Activity Index within masticatory muscles at rest on the left side when the eyes were closed. CONCLUSIONS: As refractive error increases in myopic subjects, the resting tension on the temporal muscles increases, an increase in masseter muscle thickness is noted, and a decrease in bioelectrical activity on the digastric muscle at rest.

Impact of Titanium Addition on Microstructure, Corrosion Resistance, and Hardness of As-Cast Al+6%Li Alloy.

Aluminum-lithium alloys have the potential for use in aerospace applications, and improving their physical, mechanical, and operational characteristics through alloying is a pressing task. Lithium, with a density of 0.54 g/cm3, enhances the elastic modulus of aluminum while reducing the weight of the resulting alloys, making them increasingly attractive. Adding transition metal additives to aluminum alloys enhances their strength, heat resistance, and corrosion resistance, due to their modifying effect and grain refinement. The study aimed to investigate the impact of titanium content on the microstructure, corrosion resistance, and hardness of Al-Li alloys. Four alloys were prepared with varying amounts of titanium at 0.05 wt%, 0.1 wt%, 0.5 wt%, and 1.0 wt%. The results showed that the microstructure of the alloy was modified after adding Ti, resulting in a decrease in average grain size to about 60% with the best refinement at 0.05 wt% Ti content. SEM and EDS analysis revealed an irregular net-shaped interdendritic microstructure with an observed microsegregation of Al3Li compounds and other trace elements at the grain boundaries. The samples showed casting defects due to the high content of Li in the alloy, which absorbed air during casting, resulting in casting defects such as shrinkage holes. The corrosion resistance test results were low for the samples with casting defects, with the least resistance recorded for a sample containing 0.1 wt% Ti content, with more casting defects. The addition of Ti increased the microhardness of the alloy to an average of 91.8 ± 2.8 HV.

Does cognitive function impairment affect the duration of hospitalization and in-hospital mortality in geriatric patients hospitalized for COVID-19?

AIMS: To assess the effect of cognitive function, performance of activities of daily living (ADLs), degree of depression, and fear of infection among geriatric patients hospitalized in internal medicine wards for COVID-19 on the duration of hospitalization and in-hospital mortality. METHODS: This observational survey study was conducted during the second, third, and fourth waves of the COVID-19 pandemic. The study included elderly patients of both sexes, aged ≥ 65 years, hospitalized for COVID-19 in internal medicine wards. The following survey tools were used: AMTS, FCV-19S, Lawton IADL, Katz ADL, and GDS15. The duration of hospitalization and in-hospital mortality were also assessed. RESULTS: A total of 219 patients were included in the study. The results showed that impaired cognitive function in geriatric patients (AMTS) was associated with higher in-hospital mortality among COVID-19 patients. There was no statistical significance between fear of infection (FCV-19S) and risk of death. The impaired ability to perform complex ADLs (Lawton IADL) before the onset of the disease was not associated with higher in-hospital mortality among COVID-19 patients. The diminished ability to perform basic ADLs (Katz ADL) before the onset of the disease was not associated with higher in-hospital mortality in COVID-19. The degree of depression (GDS15) was not associated with higher in-hospital mortality in COVID-19 patients. Statistically, significantly better survival was observed for patients with normal cognitive function (p = 0.005). No statistically significant differences in survival were observed in relation to the degree of depression or independence in performing ADLs. Cox proportional hazards regression analysis showed a statistically significant effect of age on mortality (p = 0.004, HR 1.07). CONCLUSION: In this study, we observe that cognitive function impairments and the older age of patients treated for COVID-19 in the medical ward increase the in-hospital risk of death.

The Influence of Visual Input on Electromyographic Activity and Patterns of Masticatory and Cervical Spine Muscles in Emmetropic Caucasian Subjects by Gender.

(1) Background: The objective of the research was to analyze the change of visual input on electromyographic activity and patterns of masticatory and cervical spine muscles in emmetropic Caucasian subjects by gender. Supposedly, visual input should not influence activity and electromyographic patterns of masticatory and cervical spine muscles in emmetropic Caucasian subjects by gender. (2) Methods: After applying the inclusion criteria, 50 emmetropic Caucasian subjects were included in the study. Four muscle pairs were analyzed: the temporalis muscle (TA), the masseter muscle (MM), the digastric muscle (DA), and the sternocleidomastoid muscle (SCM), during resting and functional activity. (3) Results: It was observed that there were no significant statistical differences in activity and bioelectrical patterns between open and closed eyes in women and men, with the exception of clenching on dental cotton rollers in DA-left and DA mean between tests in women. The observed statistical results had a small effect size, successively equal to 0.32 and 0.29. (4) Conclusions: Changes in the influence of visual input do not affect electromyographic activity and patterns of masticatory and cervical spine muscles in emmetropic Caucasian women and men.

Exploratory Study on Central Sensitization and Bioelectrical Activity of the Selected Masticatory Muscles in Subjects with Myopia.

BACKGROUND: Myopia is one of the most common eye disorders involving abnormal focusing of light rays. The studies recognize the association between the stomatognathic and visual systems. This compound may have a neurological basis associated with disorders such as central sensitization. The main aim of this study was to evaluate the influence of central sensitization on the bioelectrical activity of selected muscles of the masticatory organ in subjects with myopia. METHODS: Selected masticatory and cervical spine muscles were analyzed using an eight-channel BioEMG III electromyograph. Central sensitization was analyzed using the central sensitization inventory. RESULTS: Statistical analysis revealed significantly higher scores on the central sensitization inventory in subjects with axial myopia compared to subjects without refractive error. Repeated positive correlations were observed in the sternocleidomastoid muscle activity and negative correlations in the digastric muscle activity during open and closed eyes in myopic subjects. CONCLUSIONS: Subjects with myopia have an increased score in the central sensitization inventory. The increase in the central sensitization inventory score is connected with the changes within the electromyographic activity of the masticatory and neck muscles. The effect of central sensitization on masticatory muscle activity in myopic subjects requires further study.

The Incidence and Severity of Myopia in the Population of Medical Students and Its Dependence on Various Demographic Factors and Vision Hygiene Habits.

(1) Background: Myopia is one of the leading causes of visual impairment. Visual work and usage of electronic devices are known risk factors of myopia. Many education systems were forced to apply online and hybrid teaching methods, to reduce the number of new cases of COVID-19. Medical students are a population well-known for intense visual work in the form of learning; (2) Methods: Visual acuity and refractive error were measured in the population of medical students. Participants also filled out the survey that included their population characteristic and their habits related to the hygiene of vision; (3) Results: We found a correlation between the age of the first diagnosis of myopia and current values of refractive error. The majority of participants believe that the COVID-19 pandemic had an impact on the health of their vision. Among methods of studying, usage of the computer screen was less preferred by myopic students; (4) Conclusions: In the population of medical school students in Eastern Poland, visual acuity was lower than 1.0 in 232 (52.97%) in the right eye and 234 (53.42%) in the left eye. Early recognition of refractive error has influenced its current values. Among methods of studying, usage of the computer screen was less preferred by myopic students. More population-based studies should focus on the impact of the COVID-19 pandemic on the health of vision.

Multifunctional ZnO:Gd@ZIF-8 hybrid nanocomposites with tunable luminescent-magnetic performance for potential bioapplication.

Novel multifunctional ZnO:Gd@ZIF-8 hybrid inorganic-organic nanocomposites with tunable luminescent-magnetic performance were successfully fabricated using wet chemistry synthesis routes. Physico-chemical characterization including crystal structure, phase compositions, morphology, surface properties, as well as photoluminescent and magnetic characteristics was performed using powder X-ray diffraction (XRD), FT-IR analysis, transmission and scanning electron microscopies (TEM/SEM), N2 adsorption/desorption, SQUID magnetometer, and photoluminescence spectroscopy. The biological studies of obtained materials, such as cytotoxicity profile and in vitro MRI imaging also investigated for potential use as contrast agents. Results showed that the doping with Gd3+ in a broad concentration range and the presence of ZIF-8 layer on ZnO affect the physico-chemical properties of the obtained composites. The obtained porous ZnO:Gd@ZIF-8 composites were highly crystalline with a large surface area. The XRD study indicated the formation of hexagonal wurtzite structure for ZnO and ZnO:Gd3+ (1-5 at.%). Luminescent studies showed, that ZnO is an ideal matrix for the incorporation of Gd3+ ions in a broad concentration range with efficient green luminescence. The PL intensity reached the maximum up to 5 at.% of Gd3+. The zeta potential values indicated the good stability of obtained nanoparticles. Proposed new materials with paramagnetic behavior and outstanding MR imaging capability could be used as potential contrast agents for magnetic resonance imaging.

Concentrations of metalloproteinase-1 in patients with morphea treated with phototherapy: a preliminary study.

Introduction: Morphea (localized scleroderma) is a rare, chronic, inflammatory connective tissue disease, characterized by immune system dysfunction, vasculopathy and skin fibrosis. One of the most effective treatments is phototherapy. Phototherapy has been found to be effective in treating localized scleroderma by inducing the expression of metalloproteinase-1. Aim: To compare the concentrations of metalloproteinase (MMP-1) before psoralen and ultraviolet A (PUVA) and ultraviolet A1 (UVA1) treatments in the serum of patients with morphea. Material and methods: The observational study was conducted in one research centre and included patients with generalised morphea who were treated with PUVA and UVA1 phototherapies. The mean age of all morphea patients included in the study was 55.7 years. The levels of MMP-1 were examined by ELISA (The Biorbyt Human MMP-1 ELISA - Enzyme-Linked Immunosorbent Assay). Results: The study showed that patients treated with PUVA and UVA1 had an improvement based on clinical measures, resulting in a reduction of clinical score. However, we did not observe statistically significant differences in MMP-1 concentrations before and after treatment. Limitations: The study sample was relatively small. Further studies on a larger group of patients would be beneficial. Conclusions: Our data suggest that there is a possible correlation between MMP-1 concentrations and phototherapy. MMP-1 levels were found to be increased following phototherapy treatment, which may suggest a correlation with better response to treatment in patients with morphea. However, further research is needed.

Dual Modification of Porous Ca-P/PLA Composites with APTES and Alendronate Improves Their Mechanical Strength and Cytobiocompatibility towards Human Osteoblasts.

Synthetic implants are used to treat large bone defects that are often unable to regenerate, for example those caused by osteoporosis. It is necessary that the materials used to manufacture them are biocompatible and resorbable. Polymer-ceramic composites, such as those based on poly(L-lactide) (PLLA) and calcium phosphate ceramics (Ca-P), are often used for these purposes. In this study, we attempted to investigate an innovative strategy for two-step (dual) modification of composites and their components to improve the compatibility of composite components and the adhesion between PLA and Ca-P whiskers, and to increase the mechanical strength of the composite, as well as improve osteological bioactivity and prevent bone resorption in composites intended for bone regeneration. In the first step, Ca-P whiskers were modified with a saturated fatty acid namely, lauric acid (LA), or a silane coupling agent γ-aminopropyltriethoxysilane (APTES). Then, the composite, characterized by the best mechanical properties, was modified in the second stage of the work with an active chemical compound used in medicine as a first-line drug in osteoporosis-sodium alendronate, belonging to the group of bisphosphonates (BP). As a result of the research covered in this work, the composite modified with APTES and alendronate was found to be a promising candidate for future biomedical engineering applications.

The Preliminary Assessment of New Biomaterials Necessitates a Comparison of Direct and Indirect Cytotoxicity Methodological Approaches.

BACKGROUND: Cytotoxicity testing is a primary method to establish the safety of biomaterials, e.g., biocomposites. Biomaterials involve a wide range of medical materials, which are usually solid materials and are used in bone regeneration, cardiology, or dermatology. Current advancements in science and technology provide several standard cytotoxicity testing methods that are sufficiently sensitive to detect various levels of cellular toxicity, i.e., from low to high. The aim was to compare the direct and indirect methodology described in the ISO guidelines UNE-EN ISO 10993-5:2009 Part 5. METHODS: Cell proliferation was measured using WST-1 assay, and cytotoxicity was measured using LDH test kit. RESULTS: The results indicate that the molecular surface of biomaterials have impact on the cytotoxicity and proliferation profile. Based on these results, we confirm that the indirect method does not provide a clear picture of the cell condition after the exposure to the surface, and moreover, cannot provide complete results about the effects of the material. CONCLUSIONS: Comparison of both methods shows that it is pivotal to investigate biomaterials at the very early stages using both indirect and direct methods to access the influence of the released toxins and surface of the material on the cell condition.