Synthesis and Structural Studies of Nucleobase Functionalized Hydrogels for Controlled Release of Vitamins.

The development of biomolecule-derived biocompatible scaffolds for drug delivery applications is an emerging research area. Herein, we have synthesized a series of nucleobase guanine (G) functionalized amino acid conjugates having different chain lengths to study their molecular self-assembly in the hydrogel state. The gelation properties have been induced by the correct choice of chain lengths of fatty acids present in nucleobase functionalized molecules. The effect of alkali metal cations, pH, and the concentration of nucleobase functionalized amino acid conjugates in the molecular self-assembly process has been explored. The presence of Hoogsteen hydrogen bonding interaction drives the formation of a G-quadruplex functionalized hydrogel. The DOSY nuclear magnetic resonance is also performed to evaluate the self-assembling behavior of the newly formed nucleobase functionalized hydrogel. The nanofibrillar morphology is responsible for the formation of a hydrogel, which has been confirmed by various microscopic experiments. The mechanical behaviors of the hydrogel were evaluated by rheological experiments. The in vitro biostability of the synthesized nucleobase amino acid conjugate is also investigated in the presence of hydrolytic enzymes proteinase K and chymotrypsin. Finally, the nucleobase functionalized hydrogel has been used as a drug delivery platform for the control and sustained pH-responsive release of vitamins B2 and B12. This synthesized nucleobase functionalized hydrogel also exhibits noncytotoxic behavior, which has been evaluated by their in vitro cell viability experiment using HEK 293 and MCF-7 cell lines.

Dynamic Multicomponent Reactions-Directed Self-Assembled G-quadruplex Inherent Antibacterial Hydrogel.

Nowadays, inherent antibacterial hydrogels have gained significant attention due to their utilization against infectious bacteria. Herein, we focus on the development of an injectable, self-healable, dynamic, and G-quadruplex hydrogel with inherent antibacterial activity. The dynamic self-assembled hydrogel is constructed upon multicomponent reactions (MCR) among guanosine, 2-formylphenylboronic acid, and amino acid/peptides in the presence of potassium ions. The role of amino acid/peptides in the formation of the G-quadruplex hydrogel is studied in detail. The G-quadruplex structure is formed via the π-π stacking of G-quartets. The formation of G-quadruplex is investigated by thioflavin T binding assay, CD spectroscopy, and PXRD. The formation of the dynamic imino-boronate bond in the hydrogels is well characterized by temperature-dependent 11B NMR (VT-NMR) and FT-IR spectroscopy. Furthermore, HR-TEM images and rheological experiments reveal the fibrillar networks and viscoelastic property of the hydrogels. The presence of the dynamic imino-boronate ester bonds makes the hydrogel injectable and self-healable in nature. These dynamic G-quadruplex hydrogels show potential antibacterial activity against a series of Gram-positive and Gram-negative bacteria. The hydrogels have been used for the entrapment and sustained release of an anticancer drug doxorubicin over 48 h at different pHs (4.8, 7.4, and 8.5) and temperature without the influence of any external stimuli. Such injectable and self-healable hydrogels could be used in various applications in the field of biomedical science.

Nucleopeptide-Coupled Injectable Bioconjugated Guanosine-Quadruplex Hydrogel with Inherent Antibacterial Activity.

The multicomponent reaction-directed self-assembled hydrogels offer the opportunities to fabricate materials with ubiquitous properties which sometimes are not possible to generate from single components. Therefore, multicomponent-derived hydrogels have enormous applications in biomedical fields, and the number of such systems is increasing day by day. Herein, the multicomponent self-assembly techniques have been employed to develop a biomimetic low-molecular-weight G-quadruplex hydrogel under physiological conditions. The bioconjugation of guanosine, 4-formylphenylboronic acid, and cytosine-functionalized nucleopeptide (NP) is important to generate the multicomponent self-assembled dynamic imino-boronate ester-mediated bioconjugated G-quadruplex hydrogels. Using thioflavin T fluorescence assay, powder X-ray diffraction, and circular dichroism spectroscopic techniques, we confirm the existence of a G-quartet-like structure as the key parameter for the formation of nanofibrillar hydrogels. The multicomponent self-assembled G-quadruplex hydrogel possesses excellent inherent antibacterial activity against a broad range of bacterial species. The in vitro cytocompatibility of the synthesized hydrogel was evaluated on MCF-7 and HEK 293T cell lines to study the biocompatibility of the hydrogel. The proposed injectable, biocompatible, and NP-coupled G-quadruplex hydrogel with inherent antibacterial efficiency holds promising importance to prevent localized bacterial infections.

Death due to extensive aortic dissection with an unusual retrograde extension in a young adult.

Aortic dissection usually manifests in older individuals. It is a rare cause of sudden death in the age group <35 years. Compared to older age groups, this age range is likely to have distinct clinical and pathologic features, uncommon risk factors, and an unusual presentation. This case reports the sudden death of a 34-year-old male due to extensive aortic dissection without any previously known predisposing factors. Autopsy examination showed the presence of aortic dissection with the formation of the false lumen, which extended from the root of the aorta to the whole length of the ascending aorta, arch of the aorta and further up to 27 cm length of the descending aorta. The pathological examination also revealed retrograde involvement of the brachiocephalic artery and left common carotid artery. The reported AD belonged to Stanford 'type A'. Such extensive AD with unique retrograde extension is rarely reported in Forensic Pathology literature.

Accidental Blast Injuries While Making Indigenous Explosive Chemical Mixture: A Report of Two Incidents.

Apart from terrorist and military bombing, accidental blast injuries are the major source of morbidity and mortality in explosion occurrences. In civilian scenarios, it can happen when unskilled individuals handle explosive materials carelessly, often avoiding legal restrictions. We report two incidents of an accidental explosion in which three victims got injured during the mixing of explosive chemicals which are used in an improvised pipe gun to scare away the animals on the farm. In both incidents, the victims were mixing Gandhak (sulfur) and Potash to make an indigenous fire cracker-type explosive mixture. The victims suffered classical low-order explosion injuries. The chemical reaction between the chemicals, the treatment course of all three victims, and medico-legal implications are also discussed in the article.

Pt Nanoparticles Supported on a Dynamic Boronate Ester-Based G-quadruplex Hydrogel as a Nanoreactor.

Herein, we have reported a dynamic boronic ester mediated guanosine (G) based G-quadruplex hydrogel as an ideal template for in situ and 'green chemical' approach for the synthesis and stabilization of Pt NPs. 11 B NMR and FT-IR spectra reveal the formation of dynamic boronate ester bonds. The TEM images of the G-quadruplex hydrogel reveal entangled three-dimensional (3D) crosslink nanofibrillar networks with average diameter of 20 nm. Similarly, AFM images of the hydrogel show dense nanofibrillar assembly with an average height of 6 nm. The in situ generated Pt NPs have been characterized using TEM and XPS techniques. The average size of the nanofiber supported Pt NPs is 1.5 nm. The Pt NPs embedded G-quadruplex hydrogel shows better mechanical stiffness than the native hydrogel as the storage modulus (G') increases to 2250 Pa from 317.08 Pa after the in situ generation of Pt NPs. Furthermore, G-quadruplex hydrogel supported Pt NPs have been used as a catalytic system for hydrogenation reaction of different aromatic nitro compounds in aqueous medium. The use of G-quadruplex molecular system as a template for the synthesis and stabilization of metal NPs would be an interesting area of research.

Comparative Evaluation of Cell Block Method and Smear Cytology in Fine Needle Aspiration Cytology of Intra-abdominal Mass Lesions.

BACKGROUND & OBJECTIVE: Fine needle aspiration cytology (FNAC) is an easy, rapid, and less hazardous tool to diagnose the intra-abdominal lesions with various imaging modalities adding to its sensitivity and accuracy. However, sometimes it does not yield adequate information for precise diagnosis and the risk of false-negative and indeterminate diagnosis is always present. Cellblock preparations may be particularly helpful in such problematic cases. The current study aimed atevaluating and comparing the cytological as well as histopathological features of different intra-abdominal mass lesions. METHODS: Image-guided FNAC followed by cell block were performed on 167 patients from June 2012 to May 2013. Histologically correlated 111 cases were evaluated. Results of conventional smear, cell block, and combination of FNAC with cell block were compared with histopathological findings regarding diagnostic sensitivity, specificity, and accuracy of diagnosis. RESULTS: Cell block was more specific to diagnose these lesions than FNAC (95.49% versus 90.09%). Combined application of cell block with FNAC was more specific (96.39%) than cell block alone with 100% diagnostic accuracy. CONCLUSION: Application of a combination of cell block with FNAC was more useful to diagnose intra-abdominal mass lesions.

Sarcoma-like mural nodule in a borderline mucinous tumor of the ovary: A rare entity.

Sarcoma-like mural nodule (SLMN) is a very uncommon and misleading benign entity which may be associated with benign, borderline or malignant mucinous neoplasm of the ovary. It should be distinguished from other malignant mural nodules with sarcoma, carcinosarcoma or anaplastic carcinoma for proper management. We report a rare case of SLMN in a borderline mucinous tumor of the ovary in a 30-year-old lady. In spite of having confusing histopathological features the final diagnosis was made depending on the younger age of the patient, well circumscription of the nodule, absence of vascular invasion and immunohistochemical profile.

Ultrasound-guided aspiration cytology of retroperitoneal masses with histopathological corroboration: A study of 71 cases.

BACKGROUND: Diagnosis of retroperitoneal lesions is one of the most difficult areas in surgical pathology. Both primary and metastatic tumors can grow silently in retroperitoneum before the appearance of clinical signs and symptoms. Guided aspiration cytology has shown a promising role in diagnosis of lesions in this region. AIMS: This study was undertaken to evaluate the reliability of guided fine-needle aspiration cytology (FNAC) in the diagnosis of retroperitoneal masses and to study the spectrum of retroperitoneal lesions in a rural tertiary care hospital. MATERIALS AND METHODS: This study was done on 71 patients presenting with retroperitoneal masses over a period of 20 months in a tertiary care hospital. Ultrasound-guided FNAC was done and the smears were stained by MGG and H and E stains. Histopathological corroboration could be done on all neoplastic lesions along with some non-neoplastic lesions. RESULTS: Out of 71 cases, 48 cases (67.6%) were found to be neoplastic. Malignant tumors (35 cases) were more common than benign ones (13 cases). Malignant lesions were predominantly composed of lesions of lymph node (17 cases i.e. 48.57%) followed by sarcomas (5 cases) and germ cell tumors. Some uncommon retroperitoneal lesions like adrenal myelolipoma, renal angiomyolipoma, Burkitt's lymphoma and adrenocortical carcinoma were found in our study. Guided FNAC could diagnose all the malignant lesions with 100% accuracy except in 2 cases of poorly differentiated carcinoma which came out to be non-Hodgkin lymphoma on subsequent biopsies. CONCLUSION: Guided FNAC is an inexpensive, rapid and reliable method for diagnosis of retroperitoneal masses.