4D-Printable Photocrosslinkable Polyurethane-Based Inks for Tissue Scaffold and Actuator Applications.

4D printing recently emerges as an exciting evolution of conventional 3D printing, where a printed construct can quickly transform in response to a specific stimulus to switch between a temporary variable state and an original state. In this work, a photocrosslinkable polyethylene-glycol polyurethane ink is synthesized for light-assisted 4D printing of smart materials. The molecular weight distribution of the ink monomers is tunable by adjusting the copolymerization reaction time. Digital light processing (DLP) technique is used to program a differential swelling response in the printed constructs after humidity variation. Bioactive microparticles are embedded into the ink and the improvement of biocompatibility of the printed constructs is demonstrated for tissue engineering applications. Cell studies reveal above 90% viability in 1 week and ≈50% biodegradability after 4 weeks. Self-folding capillary scaffolds, dynamic grippers, and film actuators are made and activated in a humid environment. The approach offers a versatile platform for the fabrication of complex constructs. The ink can be used in tissue engineering and actuator applications, making the ink a promising avenue for future research.

Gold Nanoparticle Promoted Formation and Biological Properties of Injectable Hydrogels.

Acceleration of gelation in the biological environment and improvement of overall biological properties of a hydrogel is of enormous importance. Biopolymer stabilized gold (Au) nanoparticles (NPs) exhibit cytocompatibility and therapeutic activity. Hence, in situ gelation and subsequent improvement in the property of a hydrogel by employing Au NPs is an attractive approach. We report that stable Au NPs accelerate the conventional nucleophilic substitution reaction of activated halide-terminated poly(ethylene glycol) and tertiary amine functional macromolecules, leading to the rapid formation of injectable nanocomposite hydrogels in vivo and ex vivo with improved modulus, cell adhesion, cell proliferation, and cytocompatibility than that of a pristine hydrogel. NP surfaces with low chain grafting density and good colloidal stability are crucial requirements for the use of these NPs in the hydrogel formation. Influence of the structure of the amine functional prepolymer, the spacer connecting the halide leaving groups of the substrate, and the structure of the stabilizer on the rate promoting activity of the NPs have been evaluated with model low-molecular-weight substrates and macromolecules by 1H NMR spectroscopy, rheological experiments, and density functional theory. Results indicate a significant effect of the spacer connecting the halide leaving group with the macromolecule. The Au nanocomposite hydrogels show sustained co-release of methotrexate, an anti-rheumatic drug, and the Au NPs. This work provides insights for designing an injectable nanocomposite hydrogel system with multifunctional property. The strategy of the use of cytocompatible Au NPs as a promoter provides new opportunity to obtain an injectable hydrogel system for biological applications.

Biomaterials for Interfacing Cell Imaging and Drug Delivery: An Overview.

This feature article provides an overview of different kinds of futuristic biomaterials which have the potential to be used for fluorescent imaging and drug delivery, often simultaneously. The synthesis route or preparation process, fluorescence property, release profile, biocompatibility, bioimaging, and mechanistic approaches are vividly discussed. These include bioimaging with fluorescently doped quantum dots, mesoporous silica, noble metals, metal clusters, hydrophilic/hydrophobic polymers, semiconducting polymer dots, carbon/graphene dots, dendrimers, fluorescent proteins, and other nanobiomaterials. Another section discusses the controlled and targeted drug, gene, or biologically active material delivery using various vehicles such as micelles, 2D nanomaterials, organic nanoparticles, polymeric nanohybrids, and chemically modified polymers. In the last section, we discuss biomaterials, which can deliver biologically active molecules, and imaging the cell/tissue.

Sustained release of herbal drugs using biodegradable scaffold for faster wound healing and better patient compliance.

Electrospun scaffold has been developed using biodegradable polymer and age old herbal drug for efficient wound healing patch with much better patient compliance. Positively charged smaller particle size (40 nm) of the drug has been prepared for greater penetration through epidermal barrier to enhance the wound healing activity of drug. Controlled drug release has been understood in terms of interactions between the components through spectroscopic techniques and calorimetric studies. In-vivo study using albino rats shows better wound healing efficiency of scaffold in terms of higher wound area contraction, minimum inflammation, faster epithelialization and vascularization. Cellular studies also endorse the scaffold as better biomaterial. Clinical studies also demonstrate fast healing of different type of wounds in presence of all three wound dressing materials with histological evidences. The complete biodegradation of the patch confirms its green nature of the developed patch.

Modular photoorigami-based 4D manufacturing of vascular junction elements.

Four-dimensional (4D) printing, combining three-dimensional (3D) printing with time-dependent stimuli-responsive shape transformation, eliminates the limitations of the conventional 3D printing technique for the fabrication of complex hollow constructs. However, existing 4D printing techniques have limitations in terms of the shapes that can be created using a single shape-changing object. In this paper, we report an advanced 4D fabrication approach for vascular junctions, particularly T-junctions, using the 4D printing technique based on coordinated sequential folding of two or more specially designed shape-changing elements. In our approach, the T-junction is split into two components, and each component is 4D printed using different synthesized shape memory polyurethanes and their nanohybrids, which have been synthesized with varying hard segment contents and by incorporating different weight percentages of photo-responsive copper sulfide-polyvinyl pyrrolidone nanoparticles. The formation of a T-junction is demonstrated by assigning different shape memory behaviors to each component of the T-junction. A cell culture study with human umbilical vein endothelial cells reveals that the cells proliferate over time, and almost 90% of cells remain viable on day 7. Finally, the formation of the T-junction in the presence of near-infrared light has been demonstrated after seeding the endothelial cells on the programmed flat surface of the two components and fluorescence microscopy at day 3 and 7 reveals that the cells adhered well and continue to proliferate over time. Hence, the proposed alternative approach has huge potential and can be used to fabricate vascular junctions in the future.

Assessing the Relationship Between COVID-19 and Dental Decay Risk in Youth: A Retrospective Analysis.

BACKGROUND: The coronavirus disease 2019 (COVID-19) pandemic has significantly impacted public health globally, with particular attention on the effects on children, adolescents, and young adults. This study aimed to investigate the potential relationship between COVID-19 and caries risk in this age group. METHODS: A retrospective chart review was conducted on 120 patients between the ages of six and 25 years who received dental treatment at a university-affiliated dental clinic between January 2020 and December 2021. Demographic and medical data were collected, and dental examinations were performed to record the number of decayed, missing, and filled teeth (DMFT) and decayed, missing, and filled surfaces (DMFS). Data were analyzed using descriptive statistics, chi-square test or Fisher's exact test, student's t-test or Mann-Whitney U test, and multivariate regression analysis. RESULTS: Of the 120 patients, 40 were COVID-19-positive, and 32 of those patients were at high caries risk. Of the 80 patients who were COVID-19 negative, 48 were at high caries risk. There was a statistically significant association between COVID-19 exposure and caries risk. Participants who tested positive for COVID-19 had 1.8 times higher odds of dental caries than those who tested negative. However, no significant association was found between caries risk and age, gender, or previous dental history. CONCLUSION: The findings suggest that COVID-19 may be a risk factor for caries in children, adolescents, and young adults. Dental professionals should consider COVID-19 exposure as a potential risk factor when assessing caries risk in this age group. Further research is needed to better understand the mechanism underlying this association.

To Assess the Knowledge and Attitude Regarding Dental Trauma and Its Management among School Teachers.

Background: Dental traumas, particularly tooth avulsion, represent a significant dental emergency among children, frequently occurring in schools. The knowledge and immediate response of schoolteachers are crucial for the prognosis of such emergencies. Materials and Methods: This interventional study assessed the knowledge and attitudes of 248 primary school teachers in Rajasthan, India, regarding dental trauma management. Utilizing a questionnaire-based approach, the study was conducted in three phases: preintervention assessment, an informative 45-minute lecture, and a postintervention follow-up. Statistical significance was set at 5%, and the Chi-square test was employed for analysis. Results: The initial survey revealed a lack of knowledge among teachers regarding dental trauma management, with significant improvement observed in the follow-up phase post intervention. Over 90% of participants showed improved knowledge, with statistical significance (P < 0.0001). Conclusion: The study highlights a notable deficiency in school teachers' knowledge on dental trauma management initially, which significantly improved following an oral health promotion intervention. This underscores the effectiveness of educational programs in enhancing the management of dental emergencies by schoolteachers.

Autonomous Synthesis of Thin Film Materials with Pulsed Laser Deposition Enabled by In Situ Spectroscopy and Automation.

Autonomous systems that combine synthesis, characterization, and artificial intelligence can greatly accelerate the discovery and optimization of materials, however platforms for growth of macroscale thin films by physical vapor deposition techniques have lagged far behind others. Here this study demonstrates autonomous synthesis by pulsed laser deposition (PLD), a highly versatile synthesis technique, in the growth of ultrathin WSe2 films. By combing the automation of PLD synthesis and in situ diagnostic feedback with a high-throughput methodology, this study demonstrates a workflow and platform which uses Gaussian process regression and Bayesian optimization to autonomously identify growth regimes for WSe2 films based on Raman spectral criteria by efficiently sampling 0.25% of the chosen 4D parameter space. With throughputs at least 10x faster than traditional PLD workflows, this platform and workflow enables the accelerated discovery and autonomous optimization of the vast number of materials that can be synthesized by PLD.

Trends in Thyroid Nodules and Malignancy: A Two-Year Retrospective Study in a Tertiary Care Centre.

Thyroid nodules are one of the most common presentations faced by ENT clinicians, and the prevalence of differentiated thyroid cancer is increasing worldwide. We found no other study showing a clear occurence of cancer in thyroid nodules in the state of West Bengal. Hence, we undertook this study to determine the occurence of thyroid cancer among people with thyroid nodules. A retrospective review was performed for 96 patients with thyroid nodules who underwent USG and Fine Needle Aspiration Cytology (FNAC) and thyroid surgery at a tertiary hospital in Kolkata over a 2-year period from January 2020 to December 2021. The occurence of thyroid cancer in patients with thyroid nodules; association with age, sex, duration of thyroid swelling and thyroid stimulating hormone (TSH) levels of the patients; the sonographic findings (nodule size and number) and Bethesda classification on FNAC were reviewed. A total of 96 cases were reviewed. The highest malignancies were seen in swellings of 3-5 years duration (50%), and in patients with increased TSH levels (60%). Patients with single vs. multinodular goitre had comparable rates (23.07 vs 22.22%). The highest risk was seen in nodules 1-2 cm in size. A TIRADS score of 2 had a negative predictive value of 86.95% and a score of 5 had a positive predictive value of 100%. BETHESDA II lesions had a 3.44% rate of malignancy, while BETHESDA V and VI had rates of 100% and 75% respectively. While most of the thyroid swellings were benign, 22.91% were malignant, the most common being papillary carcinomas.

Oral Health Status and Treatment Needs Among Obstructive Sleep Apnea Patients in Jodhpur, Rajasthan.

Background: Obstructive sleep apnea (OSA) is a sleep disorder characterized by periodic and repetitive partial or complete collapse of the upper airway during sleep, resulting in reduced ventilation (hypopnea) or absent ventilation (apnea). Materials and Methods: The present study was conducted on 100 adult OSA patients attending hospitals of Jodhpur and the dental clinic in Vyas Dental College and Hospital in Jodhpur city. The sample consisted of 65.0% males and 35.0% females, belonging to 18 years ≥60 years of age with a mean age of 47.61 ± 8.53. Results: In our study, we have used AHI for the assessment of OSA, the major significant association (P = 0.001) was seen between AHI and periodontitis. The finding suggest that the prevalence of periodontitis is greater among patient with OSA with almost 39 patients with AHI value between 11to15 having loss of attachment between 4 mm ≥8 mm. Conclusion: Obstructive sleep apnea is acting as a significant risk factor for major Dental diseases. The study concludes that there was a significant association found between oral health status and OSA patients.

An Assessment of the Prevalence of Dental Caries, Oral Hygiene Status, Deft Index, and Oral Hygiene Habits Among Children With Special Healthcare Needs.

Background and objective Children with special healthcare needs are at an increased risk of oral health problems, including dental caries. Understanding the prevalence of dental caries, oral hygiene status, deft (decayed, extracted, filled teeth) index, and oral hygiene habits in this population is crucial for effective oral healthcare planning and interventions. The aim of this study was to assess the prevalence of dental caries, oral hygiene status, deft index, and oral hygiene habits among children aged 4-15 years with special healthcare needs in Jodhpur District, Rajasthan, India. Methods A cross-sectional study was conducted among 124 children from various, government and non-governmental organizations (NGO)-run special schools. Data on dental caries, oral hygiene status, deft index, and oral hygiene habits were collected using standardized tools and techniques. Descriptive statistics, including frequencies and percentages, were used to analyze the data. Results The prevalence of dental caries among children with special healthcare needs was 65%. The severity of dental caries varied, with 40% classified as mild, 20% as moderate, and 5% as severe. Additionally, 75% of the children exhibited poor oral hygiene, as indicated by the oral hygiene status assessment. The mean deft index score was 2.8, indicating an average dental caries experience among the participants. Regarding oral hygiene habits, 60% reported brushing their teeth once a day, while 40% reported brushing twice a day. However, a significant proportion (70%) reported non-fluoride use, and 55% stated they did not perform regular flossing. Conclusion This study highlights a high prevalence of dental caries, poor oral hygiene status, and suboptimal oral hygiene habits among children with special healthcare needs in Jodhpur District. The findings emphasize the need for targeted interventions focusing on preventive measures, oral health education, and improving access to oral healthcare for this vulnerable population. Further research with larger sample sizes and longitudinal study designs is warranted to validate these findings and develop effective strategies for enhancing oral health outcomes in children with special healthcare needs.

Tunable shape memory behavior of polymer with surface modification of nanoparticles.

In-situ inclusion of different nanoclays during synthesis results in different level of dispersion of nanoclays in the polymer matrix depending upon the surface modification of the nanoclay. Higher intercalation of the polymer chains within the galleries of organically modified nanoclay results better dispersion as compared to pristine nanoclay. The spectroscopic measurement shows that the extent of interaction between the nanoclay and polymer chains is higher in modified nanoclay nanocomposite which decreases the crystallinity considerably as compared to pristine clay nanocomposite. Interestingly, shape memory behavior measured at physiological temperature (37 °C) improves significantly in presence of organically modified nanoclay while it decreases in presence of unmodified nanoclay in same polyurethane matrix. Complete melting of soft segment along with restricted flipping of hard segment with temperature in presence of extensive interaction in nanocomposite with modified nanoclay helps it to achieve better shape memory behavior against flipping induced stacking of hard segment with temperature along with poor interaction decreases its shape memory behavior in nanocomposite with unmodified nanoclay. Temperature dependent nanostructure reveals the cause of variation in shape memory behavior in presence of organically modified nanoclay. Further, the cell culture studies like cell adhesion, cell viability assay and fluorescence imaging, suggest superior biomaterial of the nanocomposite with modified nanoclay as compared to other composite. Better biodegradable nature of the modified nanocomposite makes it suitable candidate for its potential biomedical applications.

Targeted therapy in chronic diseases using nanomaterial-based drug delivery vehicles.

The application of nanomedicines is increasing rapidly with the promise of targeted and efficient drug delivery. Nanomedicines address the shortcomings of conventional therapy, as evidenced by several preclinical and clinical investigations indicating site-specific drug delivery, reduced side effects, and better treatment outcome. The development of suitable and biocompatible drug delivery vehicles is a prerequisite that has been successfully achieved by using simple and functionalized liposomes, nanoparticles, hydrogels, micelles, dendrimers, and mesoporous particles. A variety of drug delivery vehicles have been established for the targeted and controlled delivery of therapeutic agents in a wide range of chronic diseases, such as diabetes, cancer, atherosclerosis, myocardial ischemia, asthma, pulmonary tuberculosis, Parkinson's disease, and Alzheimer's disease. After successful outcomes in preclinical and clinical trials, many of these drugs have been marketed for human use, such as Abraxane®, Caelyx®, Mepact®, Myocet®, Emend®, and Rapamune®. Apart from drugs/compounds, novel therapeutic agents, such as peptides, nucleic acids (DNA and RNA), and genes have also shown potential to be used as nanomedicines for the treatment of several chronic ailments. However, a large number of extensive clinical trials are still needed to ensure the short-term and long-term effects of nanomedicines in humans. This review discusses the advantages of various drug delivery vehicles for better understanding of their utility in terms of current medical needs. Furthermore, the application of a wide range of nanomedicines is also described in the context of major chronic diseases.

Biodegradable toughened nanohybrid shape memory polymer for smart biomedical applications.

A polyurethane nanohybrid has been prepared through the in situ polymerization of an aliphatic diisocyanate, ester polyol and a chain extender in the presence of two-dimensional platelets. Polymerization within the platelet galleries helps to intercalate, generate diverse nanostructure and improve the nano to macro scale self-assembly, which leads to a significant enhancement in the toughness and thermal stability of the nanohybrid in comparison to pure polyurethane. The extensive interactions, the reason for property enhancement, between nanoplatelets and polymer chains are revealed through spectroscopic measurements and thermal studies. The nanohybrid exhibits significant improvement in the shape memory phenomena (91% recovery) at the physiological temperature, which makes it suitable for many biomedical applications. The structural alteration, studied through temperature dependent small angle neutron scattering and X-ray diffraction, along with unique crystallization behavior have extensively revealed the special shape memory behavior of this nanohybrid and facilitated the understanding of the molecular flipping in the presence of nanoplatelets. Cell line studies and subsequent imaging testify that this nanohybrid is a superior biomaterial that is suitable for use in the biomedical arena. In vivo studies on albino rats exhibit the potential of the shape memory effect of the nanohybrid as a self-tightening suture in keyhole surgery by appropriately closing the lips of the wound through the recovery of the programmed shape at physiological temperature with faster healing of the wound and without the formation of any scar. Further, the improved biodegradable nature along with the rapid self-expanding ability of the nanohybrid at 37 °C make it appropriate for many biomedical applications including a self-expanding stent for occlusion recovery due to its tough and flexible nature.