An insight into cell-laden 3D-printed constructs for bone tissue engineering

In this review, we have spotlighted various combinations of bioinks to optimize the biofabrication of 3D bone constructs.

Effect of methanolic extract of Allium sativum (AS) in delaying cataract in STZ-induced diabetic rats

Glycemic-induced stress is a major culprit contributing to oxidative insult that has far-reaching effects in diabetic cataract worldwide. In an attempt to prevent/delay cataract, many therapeutic agents have been identified, and among these, natural dietary sources have gained pharmacological significance. Hence, we investigated the efficacy of the methanolic garlic extract against diabetic cataract in Wistar rats. Methanolic garlic extract scavenged the transition metal ion-generated H(2)O(2) with an IC(50) of 768.8 +/- 1.76 mug/ml, showing its potential ability as an antioxidant. We have noticed lenticular opacity and oxidative damage in streptozotocin (STZ)-induced hyperglycemic rats. This is evident by the elevation of Ca(2+), Cu(2+), Na(+), Mg(2+), thiobarbituric acid reacting substances (TBARS), and carbonyl content and increased activities of polyol enzymes, glutathione peroxidase (GPx), superoxide dismutase (SOD), and up regulation of iNOS transcript and protein aggregation/cross-linking followed by a decrease in reduced glutathione (GSH), K(+) content, and tryptophan fluorescence in the cataractous lenses of STZ-induced diabetic rats. Garlic administration in a dose-dependent manner attenuated the glycemia-mediated oxidative stress as all the parameters have been found normalized more or less to that of control rats and thus delaying the progression of the lens opacity. We conclude that garlic extract has hypoglycemic and anti oxidant properties that can delay the progression of cataract as revealed in this study.

DNA binding studies of antifungal drug posaconazole using spectroscopic and molecular docking methods

The binding studies of DNA with small molecules have been an emerging field of research all the time since DNA as the genetic material is a major biological target for various drugs. Interpretation of small molecule-DNA binding helps in understanding their interactions with designing new drugs of greater medicinal activity. Posaconazole is an antifungal drug in the class of triazoles which are known to possess numerous pharmacological properties. In this work, the nature of the binding of posaconazole with calf-thymus DNA has been studied using spectroscopic techniques and molecular docking studies. A binding constant of the order of 10³ M^-1 was observed from UV-visible and fluorescence studies for the interaction between posaconazole and calf-thymus DNA. The fluorescence property of posaconazole was found to be quenched by calf-thymus DNA with a quenching constant of the order of 10³ M^-1. Competitive displacement of ethidium bromide and Hoechst 33258 by posaconazole using fluorescence technique suggested minor groove binding of posaconazole in calf-thymus DNA. Confirmation of the binding mode was further complemented by the viscosity measurement and DNA melting studies followed by KI quenching experiments. The studies on the effect of ionic strength on the binding suggested a possible role of electrostatic force in the interaction. Molecular docking studies reflected a crescent shape of the posaconazole within the minor groove of calf-thymus DNA validating the experimental findings showing the residues involved in the interaction.

(E)-1-(5-Bromo-thio-phen-2-yl)-3-(3,4,5-trimeth-oxy-phen-yl)prop-2-en-1-one

In the title compound, C(16)H(15)BrO(4)S, the dihedral angle between the thio-phene and benzene rings is 13.08 (16)°. The C atoms of the meta meth-oxy groups of the substituted benzene ring lie close to the plane of the ring [displacements = 0.049 (5) and -0.022 (4) Å], whereas the para-C atom is significantly displaced [-1.052 (4) Å]. In the crystal, mol-ecules are linked by weak C-H⋯O hydrogen bonds, forming C(11) chains propagating in [100].

Chitosan-coated and thymol-loaded polymeric semi-interpenetrating hydrogels: An effective platform for bioactive molecule delivery and bone regeneration in vivo

Thymol (2-isopropyl-5-methylphenol; Thy) is a monoterpene phenolic phytocompound with medicinal properties; however, its impact on osteogenesis is yet to be thoroughly investigated. Its distribution is often hampered because of its intricate hydrophobic structure, which reduces its bioavailability. In this study, we synthesized a drug delivery vehicle using semi-interpenetrating polymer network (SIPN) hydrogels containing sodium alginate and poly(2-ethyl-2-oxazoline) (SA/Pox) loaded with Thy at varying concentrations (100, 150, and 200 μM). Subsequently, they were coated with chitosan (CS) to increase bioactivity and for sustained and prolonged release of Thy. Thy-loaded CS-coated SIPN hydrogels (SA/Pox/CS-Thy) were developed using ionic gelation and polyelectrolyte-complexation techniques. The addition of CS to hydrogels enhanced their physicochemical and material properties. These hydrogels were cytofriendly toward mouse mesenchymal stem cells (mMSCs). When mMSCs were cultured on hydrogels, Thy stimulated osteoblastic differentiation, as evidenced by calcium deposits at the cellular level. The expression of RUNX2, a key bone transcriptional factor, and other differentiation biomarkers was significantly enhanced in mMSCs cultured on SA/Pox/CS-Thy hydrogels. Notably, Thy in the SA/Pox/CS hydrogels significantly activated the TGF-β/BMP signaling pathway, which is involved in osteogenesis. A rat tibial bone defect model system revealed that the incorporation of Thy into SA/Pox/CS hydrogels augmented bone regeneration. Thus, sustained and prolonged release of Thy from the SA/Pox/CS hydrogels promoted osteoblast differentiation in vitro and bone formation in vivo. These findings shed light on the effect of Thy bioavailability in fostering osteoblast differentiation and its prospective application in bone rejuvenation.

Orsellinic acid-loaded chitosan nanoparticles in gelatin/nanohydroxyapatite scaffolds for bone formation in vitro

AIM

Orsellinic acid (2,4-Dimethoxy-6-methylbenzoic acid) (OA) is a hydrophobic polyphenolic compound with therapeutic potential, but its impact on actuating osteogenesis remains unknown. The bioavailability of OA is hampered by its hydrophobic nature. This study aimed to fabricate nano-drug delivery system-based scaffolds for OA and test its potential for osteogenesis in vitro.

MATERIALS AND METHODS

OA was loaded into chitosan nanoparticles (nCS + OA) using the ionic gelation technique at different concentrations. nCS + OA were incorporated onto the scaffolds containing gelatin (Gel) and nanohydroxyapatite (nHAp) by the lyophilization method. Biocomposite scaffolds were examined for their physicochemical and material characteristic properties. The effect of OA in the scaffolds for osteoblast differentiation was determined by alizarin red and von Kossa staining at the cellular level and by reverse transcriptase-qPCR and western blot analysis at the molecular level.

KEY FINDINGS

The scaffolds showed excellent physiochemical and material characteristics and remained cyto-friendly to mouse mesenchymal stem cells (mMSCs, C3H10T1/2). The release of OA from Gel/nHAp/nCS scaffolds enhanced the differentiation of mMSCs towards osteoblasts, as observed through cellular and molecular studies. Moreover, the osteogenic potential of OA was mediated by the activation of FAK and ERK signaling pathways through integrins.

SIGNIFICANCE

The inclusion of OA into Gel/nHAp/nCS biocomposite scaffolds at 80 μM concentration promoted osteoblast differentiation via cell adhesion mediated signaling, compared with that shown by Gel/nHAp/nCS alone. Overall, this study identified the potential therapeutic OA containing Gel/nHAp/nCS scaffolds, accelerating its potential for clinical application towards bone regeneration.

Pituitary Stalk Duplication: A Radiological Surprise in a Child With Short Stature

Objective

Pituitary stalk abnormalities are one of the causes of hypopituitarism. Isolated pituitary stalk duplication with a single pituitary gland is extremely rare with only a few cases reported to date. The present case has a different clinical picture as compared to the cases that were previously reported in the literature.

Case Report

A 2 years 6-month-old male child, a product of nonconsanguineous marriage, presented with short stature, micropenis with unilateral undescended testis, and delayed motor milestones. His bone age was delayed by 6 months. On further evaluation, he was found to be euthyroid, with stimulated growth hormone (GH) and stimulated gonadotropin levels were suboptimal, whereas the cortisol and the prolactin were normal. Magnetic resonance imaging of the pituitary revealed pituitary stalk duplication with a single pituitary gland of normal dimensions and fused tuber cinereum and mammillary body.

Discussion

To our knowledge, only 7 cases with isolated pituitary stalk duplication were reported. The presenting complaint could be primarily of hypopituitarism like short stature or a neurologic complaint or ocular abnormality. The pituitary hormone deficiencies are variable with GH deficiency being the most common as seen in our case. Other associated features could be the morning glory disc anomaly, moyamoya disease, pituitary adenoma or hypoplasia, split hypothalamus, and sellar dermoid.

Conclusion

Pituitary stalk duplication is a developmental disorder that is diagnosed only by imaging. Patients should be evaluated for hypopituitarism, particularly the GH and gonadotrophins deficiency, and also screened for associated neurologic and ocular abnormalities.

Influence of Decontaminating Agents and Swipe Materials on Laboratory Simulated Working Surfaces Wet Spilled with Sodium Pertechnetate

Context:

Decontamination of various working surfaces with sodium pertechnetate minor spillage is essential for maintaining good radiation safety practices as well as for regulatory compliance.

Aim:

To observe the influences of decontaminating agents and swipe materials on different type of surfaces used in nuclear medicine laboratory work area wet spilled with 99m-technetium (99mTc) sodium pertechnetate.

Settings and Design:

Lab-simulated working surface materials. Experimental study design.

Materials and Methods:

Direct decontamination method on dust-free lab simulated new working surfaces [stainless steel, polyvinyl chloride (PVC), Perspex, resin] using four decontaminating agents [tap water, soap water (SW), Radiacwash, and spirit] with four different swipe material [cotton, tissue paper (TP), Whatman paper (WP), adsorbent sheet (AS)] was taken 10 samples (n = 10) for each group.

Statistical Analysis:

Parametric test two-way analysis of variance is used with significance level of 0.005, was used to evaluate statistical differences between different group of decontaminating agent and swipe material, and the results are expressed in mean ± SD.

Results:

Decontamination factor is calculated after five cleaning for each group. A total of 160 samples result calculated using four decontaminating agent (tap water, SW, Radiacwash, and spirit), four swipe material (cotton, TP, WP, and AS) for commonly used surface (stainless steel, PVC, Perspex, resin) using direct method by 10 samples (n = 10) for each group.

Conclusions:

Tap water is the best decontaminating agent compared with SW, Radiac wash and spirit for the laboratory simulated stainless steel, PVC, and Perspex surface material, whereas in case of resin surface material, SW decontaminating agent is showing better effectiveness. Cotton is the best swipe material compared to WP-1, AS and TP for the stainless steel, PVC, Perspex, and resin laboratory simulated surface materials. Perspex and stainless steel are the most suitable and recommended laboratory surface material compared to PVC and resin in nuclear medicine. Radiacwash may show better result for 99mTc labelled product and other radionuclide contamination on the laboratory working surface area.

An Unusual Cause of Failed Tracheal Decannulation—A Case Report

Failure of decannulation may occur due to unexpected upper airway problems. However, the presence of a membrane in between the vocal cords is usually rare. We report a case of a 46-year-old female, who presented with focal seizures and progressed to status epilepticus. She was put on a mechanical ventilator because of hypoxic arrest. As she required prolonged ventilatory support, tracheostomy and gradual weaning from ventilator support to T-piece was done. Following stable hemodynamics, decannulation trial was attempted which failed. Subsequently, bronchoscopy was done to assess the upper airway. It revealed a thick membrane in between the vocal cords. Further examination with an indirect laryngoscope under general anesthesia confirmed the findings, and the membrance was excised. Decannulation was successful the very following day and the patient was discharged with stable hemodynamics.

Letter to the Editor: "Efficacy of subthalamic deep brain stimulation programming strategies for gait disorders in Parkinson's disease: A systematic review and meta-analysis"

This letter provides valuable insights on the recently published article titled "Efficacy of Subthalamic Deep Brain Stimulation Programming Strategies for Gait Disorders in Parkinson's Disease: A Systematic Review and Meta-Analysis." While commending the authors comprehensive review, I suggest future research focus on standardizing gait disorder classifications, conducting long-term studies to assess the durability of DBS effects and exploring adaptive DBS systems for dynamic real-time programming. Additionally, integrating advanced neuroimaging techniques could enhance our understanding of neural connectivity changes post-DBS. These recommendations could significantly improve tailored interventions and outcomes for Parkinson's disease patients with gait disturbances.

Antibacterial Effect of Biosynthesized Zinc Oxide Nanoparticles against Erwinia amylovora and Induction of Crop Growth

Objectives: Zinc oxide nanoparticles (ZnO-NPs) are widely recognized as one of the most promising types of materials in a wide range of applications, including agriculture.  Modern systemic efforts have identified several therapeutically active microalgae-derived compounds, including phenols, flavonoids and others. The antibacterial properties of the phenolic substances were demonstrated. Hence, the present study aims to exhibit the antibacterial activity of the bioactive compound capped silver nanoparticles under in vitro conditions. Methods: Bioactive compound separated by Solid-phase Extraction method. Dispersible Zinc oxide nanoparticles synthesized using the bioactive compound as the major capping agent. Zinc nitrate was used as starting material and its reduction was carried by phenolic components of Spirulina platensis aqueous extract from Zn2+ to ZnO.  The synthesized Zinc oxide nanoparticles are characterized by H1 NMR spectroscopy. Conjugated nanoparticles are characterized physically by Scanning Electron Microscopy (SEM) analysis. SEM demonstrated particle sizes in the range 10–15 nm. ZnO nanoparticles demonstrated antibacterial activity against an isolated plant pathogen Erwinia amylovora. Time kill determination assay was done. Findings: Phenols obtained after Solid Phase Extraction. Hence, this was regarded as the maximum quantified bioactive compound of Spirulina platensis. H1 NMR spectroscopy analyses showed the presence of phenolic compounds and alcohols groups of long chain were also detected. In SEM analysis, the mean diameter of spherical Phenols-ZnOPs is less than 15 nm surrounded by the capping agent. In given time periods of 4, 8, 16, and 24 hour cells, concentrations of 1000µg/mL were 42 %, 33 %, 20 %, and 18 %. At 500 µg/mL of extract concentration, Spirulina platensis inhibited 50% bacterial proliferation (IC50) of Erwinia amylovora. A significant inhibitory effect (p<0.0001) was seen against the plant pathogenic strain. Novelty: In addition to their antibacterial activities, biosynthesized ZnO-NPs are thought to show promise efficacy as growth accelerators. The most dangerous bacterial disease of pear and apple trees is fire blight, caused by Erwinia amylovora. Phenolic capped ZnO-NPs have been found to be efficient plant pathogen antagonists.

Mitochondrial Dysfunction and Imeglimin: A New Ray of Hope for the Treatment of Type-2 Diabetes Mellitus

Diabetes is a rapidly growing health challenge and epidemic in many developing countries, including India. India, being the diabetes capital of the world, has the dubious dual distinction of being the leading nations for both undernutrition and overnutrition. Diabetes prevalence has increased in both rural and urban areas, affected the younger population and increased the risk of complications and economic burden. These alarming statistics ring an alarm bell to achieve glycemic targets in the affected population in order to decrease diabetes-related morbidity and mortality. In the recent years, diabetes pathophysiology has been extended from an ominous triad through octet and dirty dozen etc. There is a new scope to target multiple pathways at the molecular level to achieve a better glycemic target and further prevent micro- and macrovascular complications. Mitochondrial dysfunction has a pivotal role in both β-cell failure and insulin resistance. Hence, targeting this molecular pathway may help with both insulin secretion and peripheral tissue sensitization to insulin. Imeglimin is the latest addition to our anti-diabetic armamentarium. As imeglimin targets, this root cause of defective energy metabolism and insulin resistance makes it a new add-on therapy in different diabetic regimes to achieve the proper glycemic targets. Its good tolerability and efficacy profiles in recent studies shows a new ray of hope in the journey to curtail diabetes-related morbidity.

Biophysical insights on the interaction of anticoagulant drug dicoumarol with calf thymus-DNA: deciphering the binding mode and binding force with thermodynamics

The biological activity of drugs is exhibited due to their interactions with bio-receptors. Dicoumarol (DIC) is a natural hydroxycoumarin and a well-known anticoagulant. DNA is the genetic material and one of the targets of numerous drugs. The interaction of DIC with calf-thymus DNA (ct-DNA) has been studied using different biophysical techniques and docking studies. The binding constant in the order of 103 to 104 M-1 was observed from spectroscopic studies. Thermodynamic studies at 4 different temperatures revealed the spontaneity of the interaction with the entropy-driven process. Marker displacement studies with competitive markers of intercalators (ethidium bromide) and groove binders (Hoechst 33258) confirmed the groove-binding nature of DIC in DNA. The groove-binding mode of DIC was complemented by different studies like viscosity measurements, DNA melting, and the effect of KI on the binding. A minor perturbation in the DNA viscosity and no significant change in the DNA melting temperature (Tm) after binding with DIC further confirms the groove binding mode. The effect of KI on the DIC and DIC-DNA system suggested the absence of DIC intercalation. The absence of significant electrostatic force was revealed from the ionic-strength effect study. Binding-induced conformational variation in ct-DNA was absent in circular dichroism studies. Molecular docking studies suggested the position of DIC within the minor groove of ct-DNA, covering three base pairs long. The outcome of this report may help in understanding the pharmacodynamics and pharmacokinetics of dicoumarol analogs and related molecules.Communicated by Ramaswamy H. Sarma.

Binding of dicoumarol analog with DNA and its antioxidant studies: A biophysical insight by in-vitro and in-silico approaches

DNA is the major target for a number of pharmaceutical drugs. The interaction of drug molecules with DNA plays a major role in pharmacokinetics and pharmacodynamics. Bis-coumarin derivatives have diverse biological properties. Here, we have explored the antioxidant activity of 3,3'-Carbonylbis (7-diethylamino coumarin) (CDC) using DPPH, H₂O_2, and superoxide scavenging studies followed by its binding mode in calf thymus-DNA (CT-DNA) using several biophysical methods including molecular docking. CDC exhibited comparable antioxidant activity to standard ascorbic acid. The UV-Visible and fluorescence spectral variations indicate the CDC-DNA complex formation. The binding constant in the range of 10⁴ M^-1 was obtained from spectroscopic studies at room temperature. The fluorescence quenching of CDC by CT-DNA suggested a quenching constant (K_SV) of 10³ to 10⁴ M^-1 order. Thermodynamic studies at 303, 308, and 318 K revealed the observed quenching as a dynamic process besides the spontaneity of the interaction with negative free energy change. Competitive binding studies with site markers like ethidium bromide, methylene blue, and Hoechst 33258 reflect CDC's groove mode of interaction. The result was complemented by DNA melting study, viscosity measurement, and KI quenching studies. The ionic strength effect was studied to interpret the electrostatic interaction and found its insignificant role in the binding. Molecular docking studies suggested the binding location of CDC within the minor groove of CT-DNA, complementing the experimental result.

An Intriguing Case of Gynecomastia in an Elderly Male as the Initial Presentation of Graves' Disease: A Case Report

Gynecomastia is the proliferation of fibroglandular tissue in the male breast due to an altered hormonal milieu between the inhibitory effect of androgens and the stimulatory effect of estrogens on the breast tissue causing feminization of the male breast. Physiological causes are more common along with a few pathological conditions leading to gynecomastia in the male population. Of these varied etiologies, thyrotoxicosis is one of the notable causes, though it is very rare in the elderly population. Gynecomastia as the initial presentation of Graves' disease that too in an elderly age group is very rare with very few cases reported in the literature. Here, we present a case of a 62-year-old male presenting with gynecomastia, who after a detailed evaluation, was diagnosed to have Graves' disease.