Polymers and their engineered analogues for ocular drug delivery: Enhancing therapeutic precision.

Ocular drug delivery is constrained by anatomical and physiological barriers, necessitating innovative solutions for effective therapy. Natural polymers like hyaluronic acid, chitosan, and gelatin, alongside synthetic counterparts such as PLGA and PEG, have gained prominence for their biocompatibility and controlled release profiles. Recent strides in polymer conjugation strategies have enabled targeted delivery through ligand integration, facilitating tissue specificity and cellular uptake. This versatility accommodates combined drug delivery, addressing diverse anterior (e.g., glaucoma, dry eye) and posterior segment (e.g., macular degeneration, diabetic retinopathy) afflictions. The review encompasses an in-depth exploration of each natural and synthetic polymer, detailing their individual advantages and disadvantages for ocular drug delivery. By transcending ocular barriers and refining therapeutic precision, these innovations promise to reshape the management of anterior and posterior segment eye diseases.

Occurrence, transport, and toxicity of microplastics in tropical food chains: perspectives view and way forward.

Microplastics, which have a diameter of less than 5 mm, are becoming an increasingly prevalent contaminant in terrestrial and aquatic ecosystems due to the dramatic increase in plastic production to 390.7 million tonnes in 2021. Among all the plastics produced since 1950, nearly 80% ended up in the environment or landfills and eventually reached the oceans. Currently, 82-358 trillion plastic particles, equivalent to 1.1-4.9 million tonnes by weight, are floating on the ocean's surface. The interactions between microorganisms and microplastics have led to the transportation of other associated pollutants to higher trophic levels of the food chain, where microplastics eventually reach plants, animals, and top predators. This review paper focuses on the interactions and origins of microplastics in diverse environmental compartments that involve terrestrial and aquatic food chains. The present review study also critically discusses the toxicity potential of microplastics in the food chain. This systematic review critically identified 206 publications from 2010 to 2022, specifically reported on microplastic transport and ecotoxicological impact in aquatic and terrestrial food chains. Based on the ScienceDirect database, the total number of studies with "microplastic" as the keyword in their title increased from 75 to 4813 between 2010 and 2022. Furthermore, various contaminants are discussed, including how microplastics act as a vector to reach organisms after ingestion. This review paper would provide useful perspectives in comprehending the possible effects of microplastics and associated contaminants from primary producers to the highest trophic level (i.e. human health).

Improving Biocompatibility for Next Generation of Metallic Implants.

The increasing need for joint replacement surgeries, musculoskeletal repairs, and orthodontics worldwide prompts emerging technologies to evolve with healthcare's changing landscape. Metallic orthopaedic materials have a shared application history with the aerospace industry, making them only partly efficient in the biomedical domain. However, suitability of metallic materials in bone tissue replacements and regenerative therapies remains unchallenged due to their superior mechanical properties, eventhough they are not perfectly biocompatible. Therefore, exploring ways to improve biocompatibility is the most critical step toward designing the next generation of metallic biomaterials. This review discusses methods of improving biocompatibility of metals used in biomedical devices using surface modification, bulk modification, and incorporation of biologics. Our investigation spans multiple length scales, from bulk metals to the effect of microporosities, surface nanoarchitecture, and biomolecules such as DNA incorporation for enhanced biological response in metallic materials. We examine recent technologies such as 3D printing in alloy design and storing surface charge on nanoarchitecture surfaces, metal-on-metal, and ceramic-on-metal coatings to present a coherent and comprehensive understanding of the subject. Finally, we consider the advantages and challenges of metallic biomaterials and identify future directions.

Impact of facial components on the attractiveness of face: A perception-based study.

INTRODUCTION: Magazines and television displays are not merely crammed with faces-they are filled with appealing faces, and both men and women are interested in a suitable partner's appearance. This study investigated what makes a face attractive and whether perception-related differences exist between facial attractiveness and facial components. METHODS: In this descriptive-analytical study, frontal and lateral view photographs of 18 young adults (9 male and 9 female) in Class I, II, and III malocclusions were assessed by 90 orthodontists, dentists, models, and laypeople using a 7-point Likert scale in terms of attractiveness. Based on scores, attractive and unattractive groups were formed. Using image analysis software, a range of defined length, angles, perimeter, and area for lips, nose, and chin were measured for the attractive group. For statistical analysis, each group was compared using a 1-way analysis of variance. Logistic regression was performed to analyze the factors of different parameters to the attractiveness of facial components. RESULTS: Overall full-face width, upper lip angle, lip area, and mentolabial angle was significantly different in all the 3 classes (P ≤0.05). In Class I malocclusion, nasolabial angle among orthodontists, nasofrontal angle among dentists, lower lip among models, and full-face width among laypeople were responsible for facial attractiveness variation. In Class II malocclusion, nose to upper lip among orthodontists, Cupid's bow among dentists, wider face among models, and upper lip among layperson were responsible for variation in facial attractiveness. In Class III malocclusion, lower lip angle among orthodontists and dentists, Cupid's bows among models and layperson was responsible for variation in facial attractiveness. CONCLUSIONS: In Class I faces, lips (Cupid's bows, lower lips, lip areas), nose (nasolabial, nasofrontal, and nasomental angles), and chin (lower lip to chin) contributed to the overall attractiveness of the face, while in Class II faces, lips (upper lip length, interbow distance, lower lip angle), nose (full facial convexity), and chin (mentolabial sulcus), as well as a greater full-face width contributed to the overall attractiveness of the face. In Class III faces, lips (lower lip angle, upper lip length), nose (nose tip angle, full facial convexity), and chin (mentolabial sulcus depth) contributed to the overall attractiveness of the face.

Advances and clinical challenges for translating nerve conduit technology from bench to bed side for peripheral nerve repair.

Injuries to the peripheral nervous system remain a large-scale clinical problem. These injuries often lead to loss of motor and/or sensory function that significantly affects patients' quality of life. The current neurosurgical approach for peripheral nerve repair involves autologous nerve transplantation, which often leads to clinical complications. The most pressing need is to increase the regenerative capacity of existing tubular constructs in the repair of large nerve gaps through development of tissue-engineered approaches that can surpass the performance of autografts. To fully realize the clinical potential of nerve conduit technology, there is a need to reconsider design strategies, biomaterial selection, fabrication techniques and the various potential modifications to optimize a conduit microenvironment that can best mimic the natural process of regeneration. In recent years, a significant progress has been made in the designing and functionality of bioengineered nerve conduits to bridge long peripheral nerve gaps in various animal models. However, translation of this work from lab to commercial scale has not been achieve. The current review summarizes recent advances in the development of tissue engineered nerve guidance conduits (NGCs) with regard to choice of material, novel fabrication methods, surface modifications and regenerative cues such as stem cells and growth factors to improve regeneration performance. Also, the current clinical potential and future perspectives to achieve therapeutic benefits of NGCs will be discussed in context of peripheral nerve regeneration.

Comparison of Canal Transportation in TruNatomy, ProTaper Gold, and Hyflex Electric Discharge Machining File Using Cone-beam Computed Tomography.

AIM: This study was carried out to compare canal transportation in three new rotary file systems, namely TruNatomy, ProTaper Gold, and Hyflex Electric Discharge Machining file system, using cone-beam computed tomography. MATERIALS AND METHODS: The study was conducted on 105 extracted teeth consisting of 60 extracted mandibular first molars and 45 mandibular second premolars involving the mesiolingual canal of mandibular first molar and the root canal of second premolar. The teeth were randomly divided into three groups of 35 out of which each group consisted of 20 mandibular first molars and 15 mandibular second premolars. The TruNatomy rotary file was used in group I, ProTaper Gold was used in group II, and Hyflex Electric Discharge Machining was used in group III. Cone-beam computed tomography scan images were obtained both before and after instrumentation. Changes caused by preparation in the coronal, middle, and apical thirds were determined on cone-beam computed tomography scans and analyzed using the Kruskal-Wallis test at p ≤ 0.05 level of significance. RESULTS: TruNatomy showed least amount of canal transportation as compared with other two file systems at all the three levels of canals. ProTaper Gold showed maximum amount of canal transportation as compared with other two file systems at all the three levels of canals. The Hyflex EDM rotary file system showed transportation, which was more than the TruNatomy file system while it was less than that of ProTaper Gold. The difference was statically significant at the middle one-third level (p = 0.03) and at the coronal level (p = 0.02). CONCLUSION: The TruNatomy system has least amount of canal transportation as compared with ProTaper Gold and Hyflex EDM system. With potential to preserve tooth structure, this file has an added advantage over other rotary file systems. CLINICAL SIGNIFICANCE: The TruNatomy file system has been recently introduced with good cyclic fatigue resistance. It is necessary to evaluate the root canal transportation caused by the TruNatomy file.

Analysis of stress distribution in lingual orthodontics system for effective en-masse retraction using various combinations of lever arm and mini-implants: A finite element method study.

INTRODUCTION: The aims and objectives of this study were to evaluate the von Mises stress and principal stress distribution and displacement of anterior teeth in a lingual orthodontics system along the periodontal ligament and alveolar bone by various combinations of mini-implants and lever arm during en-masse retraction. Four 3-dimensional finite element (FE) models of the bilateral maxillary first premolar extraction cases were constructed. METHODS: Lingual brackets were (0.018-in slots) positioned over the center of the clinical crown. In all 4 models, 150 g of retraction force was applied with the help of a nickel-titanium closed coil spring with different combinations of mini-implants and lever arm on each side. FE analysis was then performed to evaluate stress distribution, principal stress, von Mises stress, and displacement of the anterior teeth using ANSYS software (version 12.1; Ansys, Canonsburg, Pa). The FE study was enough to validate the analysis results obtained by software tools with FE simulation instead of experimental readings. Thus, statistical analysis was not required. RESULTS: In this study, maximum tensile stresses were observed in the periodontal ligament at the mesial cervical region of the canine with values of 1.84 MPa, 2.02 MPa, 1.88 MPa, and 2.08 MPa for models 1-4, respectively. Maximum von Mises stress in alveolar bone was 8.05 MPa, 8.23 MPa, 8.19 MPa, and 8.37 MPa for models 1-4, respectively, which was within the optimum limit (135 MPa). Variable amounts of displacements like lingual crown tipping, lingual root tipping, and extrusion were observed in all the models. The 15-mm long lever arm models (models 2 and 4) showed a more controlled crown (0.015 mm) and root movement (0.004 mm) compared with 12-mm long lever arm models (models 1 and 3). CONCLUSIONS: In lingual orthodontics, controlled root movement increased as we increased the length of the lever arm. It was also concluded that the amount of increased controlled tipping found with the placement of the mini-implant was toward the palatal slope.

Comparison of Mesiodistal Width of Maxillary Anteriors with Arch Form in Various Malocclusions: A Retrospective Study.

AIM: This study was conducted for evaluating and comparing the mesiodistal width of upper anteriors in different malocclusions and its relation with various arch forms. MATERIALS AND METHODS: In total, 60 subjects with different malocclusions were examined. Mesiodistal width was measured for the anterior teeth using digital vernier caliper. 3M Unitek arch form template and two-dimensional (2D) model were superimposed to find out primarily the relation of arch form in specific malocclusion to the sum the mesiodistal width of the maxillary of anterior teeth and secondarily the relation of sum of the mesiodistal width of the maxillary anterior tooth with different arch forms. RESULTS: The ovoid arch form was common in class I malocclusion with mean mesiodistal width of 50.43 mm. The tapered arch form was the common type in both class II and class III malocclusion with mean mesiodistal width of 49.96 and 45.15 mm, respectively. CONCLUSION: The mean of anterior mesiodistal width for Angle's class III individuals was 45.15 mm considerably less than that of class II subjects and class I subjects, which signifies that the tooth material was more in the anterior region of the subject of class I followed by class II and class III malocclusions. CLINICAL SIGNIFICANCE: The performed study presents various maxillary dental arch forms observed in various malocclusions (Angle's class I, class II, and class III). The ovoid and tapered arch forms exhibited the common occurrence, while the square form was the rarest.

Fabrication and characterization of graphene oxide nanoparticles incorporated in poly (vinyl alcohol) electro-spun nanofibers and its vapor-phase crosslinking.

Electrospun nanofibrous membranes have gained great focused in medical research due to its simplicity, diversity and biodegradability. The challenge to researchers is to make more effective and sustainable by incorporating pristine materials to address adverse health issues of society. In this work, considering the unique characteristics of Graphene and its derivatives, well-dispersed Graphene Oxide (GO) were prepared using Modified Hummer's method. Further, the mixture of solutions, Poly (Vinyl Alcohol) PVA with synthesized GO nano-particles, was successively fabricated into nanofibrous membranes by electrospinning technique. Further, the electrospun membranes were cross-linked through vapours of Glutaraldehyde (GA) in controlled environment to make membranes hydrophobic in nature. In addition, the characterization of synthesized GO and electrospun nanofibers were done using SEM, XRD and FTIR. The results show that GO incorporation decreases the average diameter of nanofibers from 422±133nm to 274.1±93.23nm, whereas crosslinking of nanofibers at various hours (12 to 48h) tends to increase the average diameter from 368.4±130.1nm to 671.41±293nm. In addition to that the 12h crosslinked nanofibers membrane shows better antibacterial activity than without crosslinked PVA/GO membrane against E. coli after 24h of incubation. This primarily work provides a basis for further studies of this novel nanofibrous material.

Comparative Evaluation of Nemoceph and Foxit PDF Reader for Steiner's Cephalometric Analysis.

AIM: The aim of this study was to evaluate and compare the values of Steiner's cephalometric analysis using Nemoceph and Foxit PDF Reader. No significant difference between the two methods will result in that Foxit PDF Reader can be used as a cost-effective alternative. MATERIALS AND METHODS: This study was conducted on 100 digital lateral cephalograms taken from the same machine. The samples were collected by nonprobability convenience sampling procedures. These images were analyzed for Steiner's cephalometric analysis using two software packages. RESULTS: The skeletal and dental values showed no statistically significant difference in the majority, except for the L1-NA (linear) and L1-NB (linear). CONCLUSION: Results showed that there is a high agreement between the two methods. CLINICAL SIGNIFICANCE: This article provides a simple and cost-effective method of onscreen cephalometric analysis. This technique uses the inbuilt measurement tools in the tool bar of our daily use software. The method can be used independently anywhere without any internet connection and software subscription.