Hyaluronic acid (HA), an extracellular biopolymer found throughout the human body, holds promise as a biocompatible and biodegradable scaffold material. High molecular weight (HMW) HA degrades, generating low molecular weight (LMW) fragments with distinct properties. These fragments can influence the behaviour of cells, including human dental pulp stem cells (hDPSCs) incorporated into HA-containing hydrogels or scaffolds. Therefore, a comprehensive examination of the impact of a range of HA molecular weights on hDPSCs is essential before designing HA-based scaffolds for these cells. hDPSC lines were cultured with LMW HA (800 Da, 1600 Da, 15 kDa), medium molecular weight HA (237 kDa), or HMW HA (1500 kDa) over six passages. The various molecular weights had negligible effects on hDPSCs viability, morphology, adhesion, or relative telomere length. Furthermore, the expression of key surface stemness markers (CD29, CD44, CD73, CD90) remained unaltered. HA did not induce osteogenic, chondrogenic, or adipogenic differentiation. Moreover, the potential for chondrogenic and osteogenic differentiation was not adversely affected by LMW or HMW HA. Various molecular weights of HA seem safe, biocompatible and therefore suitable components for hDPSCs-containing scaffolds. These findings affirm that the hDPCSs will not be negatively affected by HA fragments resulting from scaffold degradation.
Dentists are one of the professional groups most at risk for COVID-19 infection. Enhanced protective measures in dentistry have been adopted worldwide; however, it is unclear to what extent they were sufficient. To assess whether the protective measures outweighed the high infection risk, we compared COVID-19-related data between Czech dentists and the general Czech population. The data was obtained through a survey study attended by 15.8% of Czech Dental Chamber members. Data of the general population were acquired from the Czech Ministry of Health database. By the end of May 2022, COVID-19 full vaccination and 1st booster dose rates among study participants were 85.8% and 70.1%, respectively, which is significantly higher (p < 0.0001) compared to the Czech general population aged over 24 years (74.9% and 49.4%, respectively). To the same date, PCR/Antigen test verified COVID-19 prevalence among participants was 41.7%, and 49.9% among the general population (p < 0.0001). Prevalence and reinfection rates among individuals who received the 1st booster were significantly lower than among individuals without the booster or full vaccination (p < 0.0001). Persons who received the booster showed a faster return to work, shorter and different types of complications. Willingness to future vaccination was positive among 79.7% of respondents. Mandatory vaccination for healthcare workers and the general population was supported by 62.0% and 49.0%, respectively. The results showed that the high risk of COVID-19 infection associated with dentistry did not lead to higher COVID-19 prevalence among respondents compared to the general population.
- MeSH
- COVID-19 * epidemiologie MeSH
- databáze faktografické MeSH
- epidemie * MeSH
- lidé MeSH
- senioři MeSH
- vakcinace MeSH
- zubní lékaři MeSH
- Check Tag
- lidé MeSH
- senioři MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
- Geografické názvy
- Česká republika MeSH
The restrictions on medical students' clinical education during the COVID-19 pandemic has affected their professional readiness and often lengthened their training. These negative impacts are often considered a necessary price as clinical education is hypothesized to be associated with a high risk of pandemic spread. This work assesses this hypothesis based on COVID-19 epidemiological data among Czech dentistry students and their comparison to data of the Czech general population of similar age. We addressed two of the five Czech medical faculties (Charles University, Faculty of Medicine in Hradec Kralove and in Pilsen) providing dentistry study program with a survey. A total of 240 students participated, representing a 66.9% response rate. Over 75% of respondents participated in clinical education during the pandemic. The school environment was identified as a place of infection by only 9.8% of respondents who were aware of where they were infected. Overall, 100% of students used FFP2 respirators, and 75.3% used face shields or protective glasses while working with patients. By the end of May 2022, COVID-19 full vaccination and 1st booster rates among students were 93.8% and 54.6%, respectively, which is significantly higher (p < 0.0001, OR 7.3, 95% CI 4.4-12; p < 0.0001, OR 3.7, 95% CI 2.9-4.8, respectively) compared to their peers from the general population (67.1% and 24.4%, respectively). A total of 75.4% of respondents supported mandatory COVID-19 vaccination for healthcare professionals. To the same date, PCR and/or antigen test verified COVID-19 prevalence among students was 37.1%, while among peers from the general population, it was 45.1% (p = 0.015, OR 1.2, 95% CI 1.0-1.5). The combination of extensive protective measures and high vaccination against COVID-19 led to significantly lower COVID-19 prevalence among the students compared to their general population counterparts.
- Publikační typ
- časopisecké články MeSH
Hyaluronic acid (HA) is an acidic, non-sulfated glycosaminoglycan that is intensively studied as a biodegradable and biocompatible material for scaffolding, regenerative medicine, and clinical applications [...].
- MeSH
- biokompatibilní materiály * terapeutické užití MeSH
- kyselina hyaluronová * MeSH
- lidé MeSH
- regenerativní lékařství MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- úvodníky MeSH
Despite several scientific or ethical issues, fetal bovine serum (FBS) remains the standard nutrient supplement in the mesenchymal stem cell cultivation medium. Cell amplification plays an important role in human stem cell therapies. Increasing interest in this field has supported attempts to find suitable human alternatives to FBS for in vitro cell propagation. Human platelet lysate (hPL) has recently been determined as one of them. Our study aimed to evaluate the influence of 2% hPL in the growth medium for in vitro expansion of human natal dental pulp stem cells (hNDP-SCs). The effect was determined on proliferation rate, viability, phenotype profile, expression of several markers, relative telomere length change, and differentiation potential of four lineages of hNDP-SCs. As a control, hNDP-SCs were simultaneously cultivated in 2% FBS. hNDP-SCs cultivated in hPL showed a statistically significantly higher proliferation rate in initial passages. We did not observe a statistically significant effect on mesenchymal stem cell marker (CD29, CD44, CD73, CD90) or stromal-associated marker (CD13, CD166) expression. The cell viability, relative telomere length, or multipotency remained unaffected in hNDP-SCs cultivated in hPL-medium. In conclusion, hPL produced under controlled and standardized conditions is an efficient serum supplement for in vitro expansion of hNDP-SCs.
- MeSH
- buněčná diferenciace MeSH
- kultivované buňky MeSH
- lidé MeSH
- mezenchymální kmenové buňky * MeSH
- proliferace buněk MeSH
- živiny MeSH
- zubní dřeň * MeSH
- Check Tag
- lidé MeSH
- Publikační typ
- časopisecké články MeSH
- práce podpořená grantem MeSH
The physical stresses during cryopreservation affect stem cell survival and further proliferation. To minimize or prevent cryoinjury, cryoprotective agents (CPAs) are indispensable. Despite the widespread use of 10% dimethyl sulfoxide (DMSO), there are concerns about its potential adverse effects. To bypass those effects, combinations of CPAs have been investigated. This study aimed to verify whether high-molecular-hyaluronic acid (HMW-HA) serves as a cryoprotectant when preserving human mesenchymal stem cells (hMSCs) to reduce the DMSO concentration in the cryopreservation medium. We studied how 0.1% or 0.2% HMW-HA combined with reduced DMSO concentrations (from 10% to 5%, and 3%) affected total cell count, viability, immunophenotype, and differentiation potential post-cryopreservation. Immediately after cell revival, the highest total cell count was observed in 10% DMSO-stored hMSC. However, two weeks after cell cultivation an increased cell count was seen in the HMW-HA-stored groups along with a continued increase in hMSCs stored using 3% DMSO and 0.1% HMW-HA. The increased total cell count corresponded to elevated expression of stemness marker CD49f. The HA-supplemented cryomedium did not affect the differential potential of hMSC. Our results will participate in producing a ready-to-use product for cryopreservation of mesenchymal stem cells.
This work describes and evaluates vaccination against COVID-19 among members of the Czech Dental Chamber during the pre-booster vaccination phase. A cross-sectional online survey was conducted between 23 June and 4 September 2021, among 2716 participants, representing 24.3% of all chamber members. A total of 89.5% of respondents stated that they were registered for vaccination against COVID-19, their vaccination had started or been completed, or had a medically relevant reason to avoid vaccination. A total of 79.6% of respondents stated that they were fully vaccinated, most of them with the Comirnaty (Pfizer-BioNTech) vaccine (88.3%). The vaccination rate among males was significantly higher than among females (p = 0.001, OR 1.48). The main reasons for vaccination were professional (91.5%). The share of fully vaccinated participants was significantly higher (p < 0.0001, OR = 8.17) compared to the Czech general population (30.8%). A COVID-19 vaccine breakthrough infection rate was 0.42%. The study shows that both the willingness to vaccinate and the proportion of fully vaccinated individuals among Czech dentists are high, and only about 10% of them refused vaccination based on reasons classified as not medically relevant.
- Publikační typ
- časopisecké články MeSH
