Bio-medical materials and engineering最新文献

BackgroundOsteoporosis is a prevalent bone disease which results in increased bone porosity and decreased bone density, which in turn raises the risk of fractures. A conflict between bone formation (the process of creating new bone tissue) and bone resorption (the degradation and removal of old bone tissue) causes the disorder. This imbalance causes the process of bone remodelling to be disrupted, which weakens the bone structures.ObjectiveDue to intrinsic anatomical differences, previous research on the prediction of bone failure has been imprecise. It requires improvement for load scenarios and validation for various demographics, ultimately leading to low accuracy.MethodsTo overcome these limitations, this study proposes a novel Finite Element analysis framework for predicting osteoporosis with the mechanical properties of human bone for stress, strain estimation.ResultsAs a result of this proposed framework proves its significance with stress in healthy bones is 2.557541680090727e-04 and bones with osteoporosis is 1.814480251460656e-03, young's modulus of healthy bones and unhealthy bones are 7.019135266051970e + 10 and 0.6158529354739577e + 10, the von Mises stress for healthy bone is 2.4897e + 07, and for the unhealthy bone is 2.8638e + 07, finally, the maximum deflection in healthy bone is 1.0235e-03, for unhealthy bone is 2.1182e-03.ConclusionThus the proposed model provides significant results in the presence or absence of osteoporosis disease.

Background: Autologous bone grafting, particularly using iliac crest bone grafts, historically been considered the gold standard for bone grafting. However, its limited availability and secondary surgical trauma associated with the procedure have restricted its widespread application.

Objective: To investigate the osteogenic potential of calcium phosphate-based composites with or without the addition of bone morphogenetic protein-2 (BMP-2).

Methods: The BMP-2/calcium phosphate (CaP)/temperature-sensitive hydrogel (BCT) composite was synthesized, while the CaP/temperature-sensitive hydrogel (CT) composite was prepared as control group. The surface morphology of the composites was observed using scanning electron microscope (SEM). Subsequently, the composites were co-cultured with mouse bone marrow mesenchymal stem cells (BMSCs), and the cell proliferation, alkaline phosphatase (ALP) activity and extracellular matrix (ECM) mineralization were assessed. The composites were injected into the muscle of mice, and the samples underwent hematoxylin and eosin (HE), Masson-trichrome, and safranin and fast green staining. Immunohistochemistry for BMP-2 and type I collagen (ColI) was performed at weeks 8 and 12.

Results: There was no significant difference in cell proliferation between the BCT and CT groups. However, the relative ALP activity and ECM mineralization were significantly higher in BCT group compared to the CT group (P < 0.05). BMP-2 accelerated the osteoinduction process and promoted the formation of more new bone tissue and bone marrow in group BCT. The number of osteocytes and the collagen area ratio were significantly higher in group BCT than that in group CT (P < 0.05).

Conclusion: BMP-2 and CaP synergistically accelerated the initiation of osteoinduction, and promoted increased bone formation. The temperature-sensitive hydrogel made the material injectable, expanding its range of applications. The BCT composite shows promise as an artificial bone material.

Breast cancer is the most common cause of death among women worldwide. Early detection of breast cancer is important; for saving patients' lives. Ultrasound and mammography are the most common noninvasive methods for detecting breast cancer. Computer techniques are used to help physicians diagnose cancer. In most of the previous studies, the classification parameter rates were not high enough to achieve the correct diagnosis. In this study, new approaches were applied to detect breast cancer images from three databases. The programming software used to extract features from the images was MATLAB R2022a. Novel approaches were obtained using new fractional transforms. These fractional transforms were deduced from the fraction Fourier transform and novel discrete transforms. The novel discrete transforms were derived from discrete sine and cosine transforms. The steps of the approaches were described below. First, fractional transforms were applied to the breast images. Then, the empirical Fourier decomposition (EFD) was obtained. The mean, variance, kurtosis, and skewness were subsequently calculated. Finally, RNN-BILSTM (recurrent neural network-bidirectional-long short-term memory) was used as a classification phase. The proposed approaches were compared to obtain the highest accuracy rate during the classification phase based on different fractional transforms. The highest accuracy rate was obtained when the fractional discrete sinc transform of approach 4 was applied. The area under the receiver operating characteristic curve (AUC) was 1. The accuracy, sensitivity, specificity, precision, G-mean, and F-measure rates were 100%. If traditional machine learning methods, such as support vector machines (SVMs) and artificial neural networks (ANNs), were used, the classification parameter rates would be low. Therefore, the fourth approach used RNN-BILSTM to extract the features of breast images perfectly. This approach can be programed on a computer to help physicians correctly classify breast images.

Background: During the early postoperative period, it is important that the patient recovers without pain and inflammation, while preserving their quality of life. In this sense, coated titanium surfaces have been designed to release anti-inflammatory and analgesic drugs during the first postoperative hours.

Objective: Evaluate the adsorption capacity and release profile of different bioactive titanium surfaces treated with three different drugs: acetaminophen, doxepin and ibuprofen.

Methods: Four bioactive surfaces (polished, oxidized, hydroxyapatite precipitate, and polyvinyl alcohol coating surfaces) were physiochemically treated and analyzed.

Results: Hydroxyapatite coatings were the roughest, while PVA coating was the softest. Acetaminophen was the only drug detected on all the surfaces. In contrast, higher drug doses were loaded into the PVA coatings, showing a satisfactory release profile.

Conclusion: The results suggest that a rougher or ionically charged surface does not guarantee drug adsorption. In contrast, the use of a transport vehicle such as a polyvinyl coating ensures the release of the drug, initiating its therapeutic effect within the first minutes, and maintained for a period of between 120 and 180 min.

BackgroundHydrogels are hydrophilic polymers with high water content and a porous structure, making them suitable for incorporating water-soluble drugs and functioning as drug delivery systems. Their structural similarity to living tissues renders them valuable for applications in tissue engineering, pharmaceuticals, and medical treatments.ObjectiveThis study aimed to develop a blended hydrogel with improved mechanical strength and biocompatibility, and to enhance its drug release capabilities through electrical stimulation.MethodA conductive hydrogel was synthesized by blending gelatin methacrylate (GelMA), kappa carrageenan (k-carrageenan), and reduced graphene oxide (rGO). The hydrogel's physical integrity, biocompatibility, and drug release performance under electrical stimulation were evaluated.ResultsThe GelMA/k-carrageenan/rGO hydrogel retained its structural stability, demonstrated excellent biocompatibility, and effectively released drugs in response to electrical stimulation.ConclusionThe developed conductive hydrogel presents strong potential for advanced drug delivery systems utilizing electrical stimulation, with promising implications across biomedical and pharmaceutical fields.

BackgroundAdult newt (9-month-old) has become an emerging research model to study complete regeneration of injured adult tendon. If younger newts exhibit tendon regeneration similar to adult ones, they can be used as an additional experimental model, assuring a high- throughput of experiments using genetic manipulation owing to shorter period of growing.ObjectiveTo examine mechanical properties and tissue structure of tendon in immature Iberian ribbed newt following complete transection.MethodsDigital flexor tendon of the middle finger of the left hindlimb in 4- and 6-month-old Iberian ribbed newt (4mo and 6mo, respectively) was transected. Regenerated tendon was mechanically tested at 6 and 12 weeks postoperatively. Collagen fiber structure was also observed using two-photon microscopy.ResultsIn both 4mo and 6mo newts, regenerated tendon at 6 weeks exhibited significantly lower tensile strength than corresponding normal tendons and had unorganized collagen structure. At 12 weeks, Regenerated tendon in both groups had the strength comparable to normal controls. Additionally, the collagen structure seemed more organized compared to that at 6 weeks and comparable to controls. These phenomena were essentially similar to those in adult newts.Conclusion4mo and 6mo newts can also be used as experimental models of adult tendon regeneration research.

BackgroundResin composite restorations exhibit dimensional changes in the oral environment due to polymerization reaction and/or water sorption, which generates stresses in the surrounding tooth structures. The state of stress may differ between self-adhesive resin composites (SARCs) and conventional resin composites because only SARCs contain hydrophilic monomers.ObjectiveThe objective of this study was to evaluate the influence of water sorption on polymerization stresses of SARCs.MethodsCracks were introduced near a cylindrical hole in a glass disk, and their lengths were measured. The hole was filled with the composites. The crack lengths were repeatedly measured during 1-week water storage 37°C. Stresses at the composite-glass interface were calculated from the crack lengths and fracture toughness of the glass. Flexural moduli, water sorption and solubility of composites were also measured.ResultsPolymerization stresses of SARCs were equivalent to or less than that of a conventional composite generating relatively little stress. Significant reduction of stress occurred between 1-h and 1-day water storage in all composites. This reduction tended to be more noticeable with a larger decrease in modulus and/or larger water sorption.ConclusionsQuicker and/or larger stress reduction were considered to be beneficial for the longevity of SARC restorations.

BackgroundColon cancer (CC) refers to malignant tumor of the digestive tract worldwide and is also among the cancers with high mortality rates.ObjectiveThe aim of this work was to evaluate the diagnostic performance of multislice spiral CT (MSCT), magnetic resonance imaging (MRI), and MSCT + MRI in different stages of colon cancer (CC) (T1-T2, T3, T4). This work compared the differences in sensitivity (Sen), specificity (Spe), accuracy (Acc), and area under the curve (AUC) values among these methods and explored the optimal diagnostic strategy.MethodsA total of 120 patients with CC confirmed by pathological biopsy and 30 individuals suspected of CC but without detected tumors (as controls) were selected. All subjects underwent MSCT, MRI, and combined MSCT + MRI examinations. Statistical analyses of Sen, Spe, Acc, and AUC values were performed.ResultsIn the T1-T2 stage, MSCT had a Sen of 85.2%, Acc of 86.8%, and an AUC value of 0.878; MRI had a Spe of 91.0%, Sen of 81.6%, and an AUC value of 0.865; the combined MSCT + MRI examination had a Sen of 90.6% and an AUC of 0.903. In the T3 stage, MRI had a significantly higher Sen (91.7%) than MSCT (80.0%), with an AUC of 0.887, while the combined MSCT + MRI examination had a Sen of 98.3% and an AUC of 0.942. In the T4 stage, the combined MSCT + MRI examination performed the best, with a Sen of 100% and an AUC of 0.933, and compared with MSCT or MRI alone, the differences were statistically significant (P < 0.05).ConclusionMSCT and MRI each have their own advantages in the diagnosis of different stages of CC. MSCT is suitable for initial screening in the T1-T2 stage, while MRI is more effective in assessing tumor invasiveness in the T3 and higher stages. The combined MSCT + MRI examination can provide more comprehensive diagnostic information, especially in the T4 stage, where it shows the highest Sen and Acc. Selecting the appropriate examination method based on the patient's specific condition and staging needs is of great significance in improving the diagnostic Acc of CC.

Background: Hydrogen peroxide (H₂O₂) plays a crucial role in various industries and enzymatic reactions, including cholesterol oxidation. Cholesterol, vital for physiological functions, can lead to cardiovascular and hepatic diseases when present in excess. Accurate detection is crucial, yet current techniques are costly and time-consuming. Biosensors offer a promising alternative due to their sensitivity, speed, and portability in detecting H₂O₂. Objective: This study aims to develop a sensitive, simple, rapid, and cost-effective biosensor for H₂O₂ detection using electrospun membranes coated with polypyrrole (PPy). Methods: Poly(lactic acid) (PLA) membranes were prepared using the electrospinning technique. Subsequently, these membranes were coated with polypyrrole (PPy) through in situ chemical polymerization. The obtained materials were characterized using SEM, contact angle measurements, XPS, and their electrical properties were analyzed. Results: PLA/PPy composite membranes exhibited electrical conductivities on the order of 10^-2 S cm^-1. Upon exposure to H₂O₂ and enzymatic reaction, a significant decrease in their electrical properties was observed, indicating their potential as sensors for detecting this analyte. Conclusions: Electrospun PLA/PPy membranes demonstrate high potential for H₂O₂ detection, owing to their large surface area and high reactivity, thereby enhancing sensor sensitivity. These characteristics make this material a promising option for H₂O₂ detection applications across various industries.

BackgroundThe skin serves as a critical barrier, safeguarding the body against external threats including bacteria, viruses, and ultraviolet (UV) radiation. Compromised skin integrity can result in pain, hinder daily activities, and elevate the risk of infections. Clinically, dressings are the conventional treatment for skin injuries. However, these often necessitate frequent replacements and may exacerbate wound trauma during removal. Therefore, there is growing interest in developing innovative dressings such as hydrogels, which are celebrated for their softness, adaptability, permeability, and capacity to sustain a moist wound environment. Guar gum, a galactomannan polysaccharide extensively utilized in the food and biomedical sectors, forms highly viscous, biocompatible hydrogels that are promising for medical applications including capsules and wound dressings. Nonetheless, the mechanical strength and antimicrobial properties of guar gum hydrogels require enhancements for optimal medical efficacy.ObjectiveThis study explores the fortification of guar gum (GG) hydrogels with tannic acid (TA) and citric acid (CA), which are known for their antibacterial, anti-inflammatory, and antioxidant properties, to develop injectable, antimicrobial hydrogel dressings.MethodsEmploying a one-pot synthesis method, this research aimed to create dressings for treating skin injuries in murine models. The hydrogels were characterized using Scanning Electron Microscopy (SEM) and Fourier Transform Infrared Spectroscopy (FT-IR), assessed for antibacterial efficacy against Staphylococcus aureus, and evaluated for biocompatibility and therapeutic effectiveness in mice with full-thickness skin injuries.ResultsThe results demonstrated successful cross-linking, structural stability, and significant enhancement in wound healing, indicating the potential of these GG-CA-TA hydrogel dressings to broaden the scope of guar gum applications in clinical skin restoration.ConclusionIn this study, a kind of Guar gum hydrogel was successfully synthesized by one-pot method, which has great potential in clinical skin repair.