The Influence of Contamination and Different Cleaning Methods and the Effect of Plasma Treatment of CoCr Alloy on Tensile Bond Strength to Composite Resin.

PURPOSE: To investigate the influence of contamination and different cleaning methods on resin bonding to cobalt-chro- mium (CoCr) alloy disks. MATERIALS AND METHODS: A total of 160 CoCr disks were divided into 3 groups. The first group (N = 64) was air abraded with alumina particles and contaminated with a silicone disclosing agent and saliva; the second group (N = 64) was air abraded but not contaminated; the third group (N = 32) was neither air abraded nor contaminated. The first two groups were di- vided into 4 subgroups (N = 16) according to the cleaning method: ultrasonic bath in 99% isopropanol, use of a cleaning suspension of zirconium oxide particles, use of a cleaning suspension based on 10-MDP salt, and treatment with atmo- spheric plasma. The third group was divided into 2 subgroups (N = 16): treatment with atmospheric plasma and no treat- ment. All CoCr specimens were bonded to plexiglas tubes filled with a bonding resin that contained phosphate monomer. Tensile bond strength (TBS) was examined by tensile testing after 3 and 150 days of water storage plus 37,500 thermal cy- cles (N = 8). RESULTS: After contamination, TBS was significantly reduced after 150 days of water storage. Groups without air abrasion showed initially low TBS and debonded spontaneously after 150 days of water storage. CONCLUSION: None of the cleaning methods was able to remove saliva and silicone disclosing agent on CoCr-alloy sur- faces. Surface activation by plasma treatment has no long-term effect on the bond strength.

Organic-inorganic biohybrid films from wool-keratin/jellyfish-collagen/silica/boron via sol-gel reactions for soft tissue engineering applications.

Therapeutic angiogenesis is pivotal in creating effective tissue-engineered constructs that deliver nutrients and oxygen to surrounding cells. Hence, biomaterials that promote angiogenesis can enhance the efficacy of various medical treatments, encompassing tissue engineering, wound healing, and drug delivery systems. Considering these, we propose a rapid method for producing composite silicon-boron-wool keratin/jellyfish collagen (Si-B-WK/JFC) inorganic-organic biohybrid films using sol-gel reactions. In this approach, reactive tetraethyl orthosilicate and boric acid (pKa ⩾ 9.24) were used as silicon and boron sources, respectively, and a solid-state gel was formed through the condensation reaction of these reactive groups with the keratin/collagen mixture. Once the resulting gel was thoroughly suspended in water, the films were prepared by a casting/solvent evaporation methodology. The fabricated hybrid films were characterized structurally and mechanically. In addition, angiogenic characteristics were determined by the in ovo chick chorioallantoic membrane assay, which revealed an increased vascular network within the Si-B-WK/JFC biohybrid films. In conclusion, it is believed that Si-B-WK/JFC biohybrid films with mechanical and pro-angiogenic properties have the potential to be possessed in soft tissue engineering applications, especially wound healing.

Evaluation of falls in older persons in the emergency department during the early Coronavirus-2019 pandemic and pre-pandemic periods.

PURPOSE: This study aimed to investigate the clinical characteristics, outcomes and healthcare costs of older patients presented to the emergency department (ED) with falls in the periods before and during the Coronavirus disease-2019 (COVID-19) pandemic. METHODS: Hospital records one year before and after the onset of the COVID-19 pandemic were retrospectively analyzed through "International Statistical Classification of Diseases-10th Revision" codes. Age, gender, falls, triage classification, length of stay (LOS) in the hospital and the ED, COVID-19 status, Glasgow Coma scale, consultations-comorbidities, injury status, outcomes in the ED, and costs were recorded. RESULTS: The study comprised of 3187 patients aged ≥ 65 years admitted to the ED of a university hospital between March 2019 and 2021. In terms of pre-pandemic and pandemic periods; older patients presenting with falls to the ED, consultations, Charlson Comorbidity Index, and LOS in the ED were lower in the pandemic period, but costs were higher (p = 0.03, p = 0.01, p = 0.01, p = 0.01 and p = 0.02, respectively). Hospitalization/mortality rates were higher in COVID-19 positive patients (77.2%) than in COVID-19 negative patients (4.6%) within the pandemic period and the patients in the pre-pandemic period (22.8%), and the costs, as well (both p = 0.01). CONCLUSION: Though the number of fall-related presentations of older persons to the ED, comorbidity burden, consultations, and the LOS in the ED was lower, direct costs were higher during the pandemic period, particularly for COVID-19 positive older patients admitted to ED with falls than the pre-pandemic period, and those patients were with poorer outcomes.

Are YouTube videos claiming to describe lumbar spinal manipulation techniques adequate?

BACKGROUND AND OBJECTIVE: YouTube has become a digital visual library in almost all fields of life, including medicine. Healthcare professionals and students frequently use YouTube to gain new skills and knowledge; however, the content of these videos has not been scientifically evaluated. Therefore, this study aimed to determine the descriptive adequacy and quality of YouTube videos on lumbar spine manipulation techniques (LSMTs) prepared by different healthcare professionals. METHODS: The first 50 most relevant videos retrieved on searching YouTube for the keyword 'lumbar spinal manipulation techniques' were included in the study. The video metrics (total duration, number of views, time since upload, number of comments, number of likes, and number of dislikes) that could be accessed from video descriptions were recorded. However the videos were scored according to manipulation definition criteria proposed by the American Academy of Orthopedic Manual Physical Therapists (AAOMPT manipulation description score - AAOMPT-MDS) and benchmark criteria for quality of digital content by the Journal of American Medical Association's (JAMA). The video metrics, AAOMPT-MDS and JAMA scores of the videos prepared by medical doctors, chiropractors, osteopaths, and physiotherapists were compared. RESULTS: Video metrics of groups were similar. The mean AAOMPT-MDS of the videos was 2.40 ± 1.57 out of 6.00 (higher score was better), and the mean JAMA score was 2.14 ± 1.05 out of 4.00 (higher score was better). Videos created by all professional groups had statistically comparable AAOMPT-MDS and JAMA scores (p > 0.05). CONCLUSION: Although YouTube videos on LSMTs offer valuable information for professionals and students, creators should follow the proposed recommendations when producing these videos to ensure quality content and systematic presentation.

Is Cam Pincer Deformity a Predisposing Factor for Patellofemoral Pain Syndrome?

Purpose: This study aimed to investigate whether cam and pincer deformities (CPDs) are a risk factor for patellofemoral pain syndrome (PFPS) in women. In addition, it sought to compare the hip joint range of motion and the hip muscle strength of extremities with and without CPDs and PFPS. Materials and Methods: A total of 82 hips of 41 women with PFPS were included in the study. The mean age of participants was 32.07 ± 7.13 years. The presence of CPDs was detected on digital anterior pelvis radiographs. Pain was evaluated using the visual analog scale, and function using the Kujala scoring system. Maximum isometric muscle strength around the hips was measured using a hand-held dynamometer. Hip joint range of movement angles were measured in all three planes using a universal goniometer. Results: CPDs were found to predict PFPS in women (p = 0.011, p = 0.048). The rate of CPDs was significantly higher in extremities with PFPS compared to those without PFPS (p = 0.007). The Kujala scores of extremities with cam deformity were significantly lower than those of extremities without pincer deformity (p = 0.043). The internal/external muscle strength ratio was greater, and the abduction/adduction muscle strength ratio was lower in extremities with cam and PFPS than in those without (p = 0.040, p = 0.049). The external rotation and abduction range of movement angles were significantly smaller in extremities with pincer and PFPS compared to those without (p = 0.043, p = 0.035). Conclusion: CPDs may be a structural predisposing factor in the development of PFPS in women. CPDs assessment when evaluating predisposing factors for PFPS may present an opportunity for the management of PFPS.

3D Printing of Extracellular Matrix-Based Multicomponent, All-Natural, Highly Elastic, and Functional Materials toward Vascular Tissue Engineering.

3D printing offers an exciting opportunity to fabricate biological constructs with specific geometries, clinically relevant sizes, and functions for biomedical applications. However, successful application of 3D printing is limited by the narrow range of printable and bio-instructive materials. Multicomponent hydrogel bioinks present unique opportunities to create bio-instructive materials able to display high structural fidelity and fulfill the mechanical and functional requirements for in situ tissue engineering. Herein, 3D printable and perfusable multicomponent hydrogel constructs with high elasticity, self-recovery properties, excellent hydrodynamic performance, and improved bioactivity are reported. The materials' design strategy integrates fast gelation kinetics of sodium alginate (Alg), in situ crosslinking of tyramine-modified hyaluronic acid (HAT), and temperature-dependent self-assembly and biological functions of decellularized aorta (dAECM). Using extrusion-based printing approach, the capability to print the multicomponent hydrogel bioinks with high precision into a well-defined vascular constructs able to withstand flow and repetitive cyclic compressive loading, is demonstrated. Both in vitro and pre-clinical models are used to show the pro-angiogenic and anti-inflammatory properties of the multicomponent vascular constructs. This study presents a strategy to create new bioink whose functional properties are greater than the sum of their components and with potential applications in vascular tissue engineering and regenerative medicine.

Effect of demographic features on morphometric variables of the knee joint: Sample of a 20 to 40-year-old Turkish population.

This study aimed to investigate the relationship between body mass index (BMI), age, and sex and morphological risk factors that may cause internal knee injuries. The magnetic resonance images of 728 participants who met the inclusion criteria and had a mean age of 34.4 ±â€…6.8 years were analyzed retrospectively. Demographic differences were analyzed by measuring 17 morphological parameters known to be associated with internal knee injuries. Men had a higher anterior cruciate ligament length (ACLL), anterior cruciate ligament width, (ACLW) lateral femoral condylar width (LFCW), medial femoral condylar width (MFCW), lateral femoral condylar depth (LFCD), distal femoral width (DFW), and intercondylar femoral width (IFW) than women (P < .05). By contrast, the medial meniscus bone angle (MMBA) was lower in men than in women (P < .05). Women aged 31 to 40 years had a lower Insall-Salvati index (ISI) and lateral tibial posterior slope (LTPS) than those aged 21 to 30 years (P < .05), whereas men aged 31 to 40 years had a lower ISI than those aged 21 to 30 years (P < .05). Women with BMI ≥ 30 had a higher LFCW and MFCW but a lower ISI than those with BMI < 30 (P < .05). Men with BMI ≥ 30 had a higher LFCW, MFCW, DFW, and MMBA than those with BMI < 30 (P < .05). The use of value ranges structured according to demographic characteristics, rather than a single value range for all patient groups, may contribute to the evaluation and treatment of the morphological features that are thought to be effective in the development of internal knee injuries. These values may also shed light on future radiological risk scoring systems and artificial intelligence applications in medicine.

The effect of a supervised online group exercise program on symptoms associated with patellofemoral pain syndrome in women.

BACKGROUND: Patellofemoral pain syndrome (PFPS) is one of the musculoskeletal system pathologies frequently encountered especially in women. OBJECTIVE: The aim of the current study was to compare the efficacy of an online exercise program with a home exercise program including the same exercises, and a control group planned for females with PFPS. METHODS: The study included 60 females with PFPS aged 33.17 ± 6.84. Participants were randomly divided into 3 groups. One of the groups was given a 6-week home program consisting of evidence-based exercises. Exercises consisting of the same exercises were supervised online to another group. The third group did not receive any intervention. Pain, knee joint range of motion, muscle strength in flexion and extension and hip posterolateral muscle group, patellofemoral joint functionality, quality of life, recurrence of injury and fear of movement were measured at preintervention and postintervention. RESULTS: Participation in the online supervised exercise group was seen to result in a greater decrease in pain during activity and kinesiophobia, and a greater increase in the quality of life mental health sub-dimension compared to the home exercise group. CONCLUSION: Online supervised exercise groups could be an alternative telerehabilitation method for exercise programs established for women with PFPS.

Decellularized Bone Extracellular Matrix-Coated Electrospun PBAT Microfibrous Membranes with Cell Instructive Ability and Improved Bone Tissue Forming Capacity.

Current approaches to develop bone tissue engineering scaffolds have some limitations and shortcomings. They mainly suffer from combining mechanical stability and bioactivity on the same platform. Synthetic polymers are able to produce mechanically stable sturctures with fibrous morphology when they are electrospun, however, they cannot exhibit bioactivity, which is crucial for tissue engineering and regenerative medicine. One current strategy to bring bioactivity in synthetic materials is to combine extracellular matrix (ECM)-sourced materials with biologically inert synthetic materials. ECM-sourced materials without any modifications are mechanically unstable; therefore, reinforcing them with mechanically stable platforms is indispensable. In order to overcome this bifacial problem, we have demonstrated that poly(butylene adipate-co-terephthalate) (PBAT) electrospun microfibrous membranes can be successfully modified with decellularized bone ECM to endow fibers with bioactive hydrogel and mimic natural micro-features of the native bone tissue. The developed structures have been shown to support osteogenesis, confirmed by histochemical staining and gene expression studies. Furthermore, ECM-coated PBAT fibers, when they were aligned, supplied an improved level of osteogenesis. The strategy demonstrated can be adapted to any other tissues, and the emerging microfibrous, mechanically stable, and bioactive materials can find implications in the specific fields of tissue engineering and regenerative medicine.

Synthesis of Silica-Based Boron-Incorporated Collagen/Human Hair Keratin Hybrid Cryogels with the Potential Bone Formation Capability.

Tissue engineering and regenerative medicine have evolved into a different concept, the so-called clinical tissue engineering. Within this context, the synthesis of next-generation inorganic-organic hybrid constructs without the use of chemical crosslinkers emerges with a great potential for treating bone defects. Here, we propose a sophisticated approach for synthesizing cost-effective boron (B)- and silicon (Si)-incorporated collagen/hair keratin (B-Si-Col-HK) cryogels with the help of sol-gel reactions. In this approach, collagen and hair keratin were engaged with a B-Si network using tetraethyl orthosilicate as a silica precursor, and the obtained cryogels were characterized in depth with attenuated total reflectance-Fourier transform infrared spectroscopy, solid-state NMR, X-ray diffraction, thermogravimetric analysis, porosity and swelling tests, Brunauer-Emmett-Teller and Barrett-Joyner-Halenda analyses, frequency sweep and temperature-dependent rheology, contact angle analysis, micromechanical tests, and scanning electron microscopy with energy dispersive X-ray analysis. In addition, the cell survival and osteogenic features of the cryogels were evaluated by the MTS test, live/dead assay, immuno/histochemistry, and quantitative real-time polymerase chain reaction analyses. We conclude that the B-Si-networked Col-HK cryogels having good mechanical durability and osteoinductive features would have the potential bone formation capability.

A novel method for constructing an acellular 3D biomatrix from bovine spinal cord for neural tissue engineering applications.

In this study, we aimed at generating 3-dimensional (3D) decellularized bovine spinal cord extracellular matrix-based scaffolds (3D-dCBS) for neural tissue engineering applications. Within this scope, bovine spinal cord tissue pieces were homogenized in 0.1 M NaOH and this viscous mixture was molded to attain 3D bioscaffolds. After resultant bioscaffolds were chemically crosslinked, the decellularization process was conducted with detergent, buffer, and enzyme solutions. Nuclear remnants in the native tissue and 3D-dCBS were determined with DNA content analysis and agarose gel electrophoresis. Afterward, 3D-dCBS were biochemically characterized in depth via glycosaminoglycan (GAG) content, hydroxyproline (HYP) assay, and sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE). Cellular survival of human adipose-derived mesenchymal stem cells (hAMSCs) on the 3D-dCBS for 3rd, 7th, and 10th days was assessed via MTT assay. Scaffold and cell/scaffold constructs were also evaluated with scanning electron microscopy and histochemical studies. DNA contents for native and 3D-dCBS were respectively found to be 520.76 ± 18.11 and 28.80 ± 0.20 ng/mg dry weight (n = 3), indicating a successful decellularization process. GAG content, HYP assay, and SDS-PAGE results proved that the extracellular matrix was substantially preserved during the decellularization process. In conclusion, it is believed that the novel decellularization method may allow fabricating 3D bioscaffolds with desired geometry from soft nervous system tissues.

A Novel Protocol to Generate Decellularized Bovine Spinal Cord Extracellular Matrix-Based Scaffolds (3D-dCBS).

Extracellular matrix (ECM)-based tissue engineering scaffolds have an essential role in promoting tissue regeneration. Nerve tissue engineering aims at facilitating the repair of permanent damage to the peripheral and central nervous systems, which are difficult to heal. For this purpose, a variety of biomaterials are being developed consisting of numerous synthetic and/or natural polymers to provide axonal reinnervation and to direct the growth of axons. Here, we present a novel protocol that enables to fabricate a 3-dimensional (3D) decellularized scaffold derived from the bovine spinal cord (BSC) ECM (3D-dCBS) for neural tissue engineering applications. In this protocol, a viscous ECM-derived gel from BSC is prepared, molded, and chemically crosslinked with EDC/NHS (3D-CBS) before decellularization process. Decellularization of 3D-CBS is performed with 1% SDS to attain 3D-dCBS. As compared with other available methods, our protocol is a novel decellularization method that preserves a more significant part of the ECM. We believe that the mentioned protocol has the potential to produce a bioengineered scaffold from spinal cord tissue with desired geometry for regenerative medicine applications related to neural tissue engineering.

Trans-differentiation of human adipose-derived mesenchymal stem cells into cardiomyocyte-like cells on decellularized bovine myocardial extracellular matrix-based films.

In this study, we aimed at fabricating decellularized bovine myocardial extracellular matrix-based films (dMEbF) for cardiac tissue engineering (CTE). The decellularization process was carried out utilizing four consecutive stages including hypotonic treatment, detergent treatment, enzymatic digestion and decontamination, respectively. In order to fabricate the dMEbF, dBM were digested with pepsin and gelation process was conducted. dMEbF were then crosslinked with N-hydroxysuccinimide/1-Ethyl-3-(3-dimethylaminopropyl)-carbodiimide (NHS/EDC) to increase their durability. Nuclear contents of native BM and decellularized BM (dBM) tissues were determined with DNA content analysis and agarose-gel electrophoresis. Cell viability on dMEbF for 3rd, 7th, and 14th days was assessed by MTT assay. Cell attachment on dMEbF was also studied by scanning electron microscopy. Trans-differentiation capacity of human adipose-derived mesenchymal stem cells (hAMSCs) into cardiomyocyte-like cells on dMEbF were also evaluated by histochemical and immunohistochemical analyses. DNA contents for native and dBM were, respectively, found as 886.11 ± 164.85 and 47.66 ± 0.09 ng/mg dry weight, indicating a successful decellularization process. The results of glycosaminoglycan and hydroxyproline assay, and sodium dodecyl sulfate polyacrylamide gel electrophoresis (SDS-PAGE), performed in order to characterize the extracellular matrix (ECM) composition of native and dBM tissue, showed that the BM matrix was not damaged during the proposed method. Lastly, regarding the histological study, dMEbF not only mimics native ECM, but also induces the stem cells into cardiomyocyte-like cells phenotype which brings it the potential of use in CTE.

Fabrication of human hair keratin/jellyfish collagen/eggshell-derived hydroxyapatite osteoinductive biocomposite scaffolds for bone tissue engineering: From waste to regenerative medicine products.

In the present study, we aimed at fabricating an osteoinductive biocomposite scaffold using keratin obtained from human hair, jellyfish collagen and eggshell-derived nano-sized spherical hydroxyapatite (nHA) for bone tissue engineering applications. Keratin, collagen and nHA were characterized with the modified Lowry method, free-sulfhydryl groups and hydroxyproline content analysis, sodium dodecyl sulfate-polyacrylamide gel electrophoresis (SDS-PAGE), attenuated total reflectance-fourier transform infrared spectroscopy (ATR-FTIR) and thermal gravimetric analysis (TGA) which confirmed the success of the extraction and/or isolation processes. Human adipose mesenchymal stem cells (hAMSCs) were isolated and the cell surface markers were characterized via flow cytometry analysis in addition to multilineage differentiation capacity. The undifferentiated hAMSCs were highly positive for CD29, CD44, CD73, CD90 and CD105, but were not seen to express hematopoietic cell surface markers such as CD14, CD34 and CD45. The cells were successfully directed towards osteogenic, chondrogenic and adipogenic lineages in vitro. The microarchitecture of the scaffolds and cell attachment were evaluated using scanning electron microscopy (SEM). The cell viability on the scaffolds was assessed by the MTT assay which revealed no evidence of cytotoxicity. The osteogenic differentiation of hAMSCs on the scaffolds was determined histologically using alizarin red S, osteopontin and osteonectin stainings. Early osteogenic differentiation markers of hAMSCs were significantly expressed on the collagen-keratin-nHA scaffolds. In conclusion, it is believed that collagen-keratin-nHA osteoinductive biocomposite scaffolds have the potential of being used in bone tissue engineering.