Nanoapatite-Loaded κ-Carrageenan/Poly(vinyl alcohol)-Based Injectable Cryogel for Hemostasis and Wound Healing.

Immediate control of excessive bleeding and prevention of infections are of utmost importance in the management of wounds. Cryogels have emerged as promising materials for the rapid release of medication and achieving hemostasis. However, their quick release properties pose the challenge of exposing patients to high concentrations of drugs. In this study, hybrid nanocomposites were developed to address this issue by combining poly(vinyl alcohol) and κ-carrageenan with whitlockite nanoapatite (WNA) particles and ciprofloxacin, aiming to achieve rapid hemostasis and sustained antibacterial effects. A physically cross-linked cryogel was obtained by subjecting a blend of poly(vinyl alcohol) and κ-carrageenan to successive freezing-thawing cycles, followed by the addition of WNA. Furthermore, ciprofloxacin was introduced into the cryogel matrix for subsequent evaluation of its wound healing properties. The resulting gel system exhibited a 3D microporous structure and demonstrated excellent swelling, low cytotoxicity, and outstanding mechanical properties. These characteristics were evaluated through analytical and rheological experiments. The nanocomposite cryogel with 4% whitlockite showed extended drug release of 71.21 ± 3.5% over 21 days and antibacterial activity with a considerable growth inhibition zone (4.19 ± 3.55 cm). Experiments on a rat model demonstrated a rapid hemostasis property of cryogels within an average of 83 ± 4 s and accelerated the process of wound healing with 96.34% contraction compared to the standard, which exhibited only ∼78% after 14 days. The histopathological analysis revealed that the process of epidermal re-epithelialization took around 14 days following the skin incision. The cryogel loaded with WNAs and ciprofloxacin holds great potential for strategic utilization in wound management applications as an effective material for hemostasis and anti-infection purposes.

Facile synthesis of mixed O, S or Se bearing hexasubstituted benzenes and their potential as Cu(ii) ion probe.

The present study offers a facile route for the synthesis of unsymmetrical hexasubstituted benzenes bearing alternate heteroatoms (O, S and Se) with the formula [1,3,5-(RSeCH2)3-2,4,6-(R'ECH2)3C6] (E = O, S or Se). The synthetic protocol involves the use of an in situ generated tris(selenonium) ion followed by treatment with another nucleophile affording the targeted species in >70% yields. The unsymmetrical hexasubstituted derivatives were characterized on the basis of physicochemical and spectroscopic data and in a representative case with single crystal X-ray study. The current work assumes great significance as the potential of these species as "turn-off" chemical sensors for Cu2+, which is a biologically and environmentally crucial metal ion, was also successfully demonstrated by 5a which bears alternate oxygen and selenium centres.

En Route Activity of Hydration Water Allied with Uranyl (UO22+) Salts Amid Complexation Reactions with an Organothio-Based (O, N, S) Donor Base.

This study provides en route activity of hydration water allied with uranyl salts amid complexation reactions with a donor species L bearing O, N, and S (phenolic, -OH; imine, -HC═N-; and thio-, -S-) donor functionalities. The UO22+/L reaction encounters a series of hydrolytic steps with hydration water released from uranyl salts during the complexation processes. Primarily, the coordinated [L(-HC=N)(OH)(-HC=N) → UO2(NO3)2/(OAc)2] species formed during the complexation process undergoes partial hydrolysis of the coordinated ligand resulting in the isolation of an aldehyde coordinated uranyl species [L(-HC=N)(OH)(-HC=O) → UO2(NO3)2/(OAc)2]. The influence of hydration water continued as the reaction further proceeded to the next stage resulting in alteration of the aldehyde coordinated uranyl species [L(-HC=N)(OH)(-HC=O) → UO2(NO3)2/(OAc)2] to an oxidized carboxy coordinated uranyl species [L(-HC=N) (OH){-C(═O)O} → (NO3)/(OAc)]2 without the use of any external oxidizing agents. These studies are of particular significance as they allow one to realize the adventitious role of hydration water released from commonly used uranyl salts during their reaction with organic donor substrates in nonaqueous medium. These results also form an experimental basis to understand the critical behavior of UO22+ ion activity (as oxidizing, reducing, or catalytic) relevant in many chemical, biological, and environmental processes.

Synthesis and preliminary biological evaluation for the anticancer activity of organochalcogen (S/se) tethered chrysin-based organometallic RuII(η6-p-cymene) complexes.

Organochalcogen (S/Se) functionalized chrysin derivatives were synthesized and coordinated with RuII(η6-p-cymene) to efficiently form ruthenium-based chemotherapeutic drug entities [C31H35O4SRuCl]; [C31H35O4SeRuCl]; [C33H31O4SRuCl]; and [C33H31O4SeRuCl]. The complexes were thoroughly characterized by analytical and various spectroscopic techniques which include elemental analysis, UV-vis, IR, NMR (1H, 13C, and 77Se NMR), and HR-MS. The interaction studies of these Ru(II) complexes were carried out with CT DNA/HSA by employing UV-vis, fluorescence and circular dichroic techniques in view to examine their chemotherapeutic potential. The complexes demonstrated predominant binding toward CTDNA via electrostatic interaction while, the extent of binding was quantified by calculating intrinsic binding constant (Kb) and binding constant (K) values which revealed higher binding affinity of selenium-based chrysin complexes as compared to their thio-analogs, following the order [C31H35O4SeRuCl] > [C33H31O4SeRuCl] > [C31H35O4SRuCl] > [C33H31O4SRuCl]. Moreover, interaction of these complexes with human serum albumin (HSA) was also investigated which suggested spontaneous interactions of complexes with the protein by hydrogen bonding and van der Waals forces. To visualize the preferential binding sites and affinity of complexes with DNA and HSA molecular docking studies were performed. Additionally, in vitro anticancer activity of the complexes were evaluated by SRB assay on selected cancer cell lines viz., HeLa (cervical), MIA-PA-CA-2 (pancreatic), MCF-7 (breast), Hep-G2 (Hepatoma), and SK-OV-3 (ovarian) which exhibited the superior cytotoxicity of complex [C31H35O4SeRuCl] as compared to other analogs on selective cancer phenotypes. Communicated by Ramaswamy H. Sarma.

Responsive nature of 1,2,4,5-tetrakis(2-pyridylthiomethyl)benzene toward group 12 metal nitrates: activity of coordinated nitrate in metal complexes.

This study provides a detailed analysis on the responsive behavior of 1,2,4,5-tetrakis(2-pyridylthiomethyl)benzene (L) toward group 12 metal nitrates in both aqueous and nonaqueous media. The ligand L proved to be an environmentally responsive species, and structural investigations of its complexes with respective M(NO3)2 (M = Zn, Cd, and Hg) allowed one to remark on the inherent activity of the nitrate ion, resulting in a distinctively higher coordination number and dimensionality to the metal cations.

An organoselenium-based highly sensitive and selective fluorescent "turn-on" probe for the Hg2+ ion.

An organoselenium-based NSe(3) type of tripodal system 2 as a Hg(2+)-selective fluorescence "turn-on" probe is described. The "turn-on" fluorescence behavior of this selenotripod 2 is significant because it depends on Hg-Se bond formation and acts as a reporting unit for this system. The system exhibits immediate response (15 s) with a subnanomolar detection limit (0.1 nM) for the Hg(2+) ion. It efficiently detects both aqueous and nonaqueous Hg(2+) at 2 nM concentration.