Luminita Marin

Luminita Marin
Petru Poni Institute of Macromolecular Chemistry · Laboratory of Polycondensation and Thermostable Polymers

Dr. Habil.
chitosan, hydrogels, electrospinning, liquid crystals

About

119
Publications
10,049
Reads
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Introduction
Chitosan based materials, including hydrogels, nanofibers, formulations for drug delivery or fertilizer release. Phenothiazine based materials for optoelectronic and biomedical applications, including design and synthesis of new compounds, and preparation of nanocrystals, cocrystals, blends or composites.
Additional affiliations
May 2013 - August 2013
European Institute of Membranes
Position
  • PostDoc Position
Description
  • Synthesis of non-viral vectors based on reversible imine linkages.
March 2011 - June 2020
European Institute of Membranes
Position
  • PostDoc Position
Description
  • Synthesis of dynamic materials based on chitosan.
January 2006 - July 2006
Italian National Research Council
Position
  • young visitor

Publications

Publications (119)
Article
Full-text available
Supramolecular hydrogels based on chitosan and monoaldehydes are biomaterials with high potential for a multitude of bioapplications. This is due to the proper choice of the monoaldehyde that can tune the hydrogel properties for specific practices. In this conceptual framework, the present paper deals with the investigation of a hydrogel as bioabso...
Article
The purpose of the study was to develop new antimicrobial hydrogels from natural resources that may promote wound healing and prevent bacterial skin infection. The new hydrogels were synthesized by crosslinking chitosan with a vanillin isomer, 5-methoxysalicylaldehyde, by a friendly and easy method. To characterize these hydrogels, their structural...
Article
Full-text available
Glioblastoma (GBM) is a lethal brain cancer with a very difficult therapeutic approach and ultimately frustrating results. Currently, therapeutic success is mainly limited by the high degree of genetic and phenotypic heterogeneity, the blood brain barrier (BBB), as well as increased drug resistance. Temozolomide (TMZ), a monofunctional alkylating a...
Article
Full-text available
Microporous chitosan nanofibers functionalized with different amounts of an antimicrobial agent via imine linkage were prepared by a three-step procedure including the electrospinning of a chitosan/PEO blend, PEO removal and acid condensation reaction in a heterogeneous system with 2-formylphenylboronic acid. The fibers’ characterization was undert...
Chapter
Full-text available
Phenothiazine based compounds are well known for their successful application in bio-medicine. Used for many years for the synthesis of many classes of drugs, in the last two decades the phenothiazine derivatives proved a promising potential for the cancer treatment. Taking into account phenothiazine properties and poly(ethylene glycol) biocompatib...
Chapter
Biocompatible hydrogels were synthesized from chitosan and 2-formylphenylboronic acid (2-FPBA), by the acid condensation reaction of chitosan’s amine groups and aldehyde group of 2-FPBA. FTIR and NMR spectroscopy demonstrated that the hydrogelation is a consequence of the formation of reversible imine linkages between the reagents, while wide angle...
Article
The paper presents the synthesis and characterization of poly(trimethylene carbonate) grafted chitosan as a new water soluble biopolymer suitable for in vivo applications. The synthesis was performed via ring-opening polymerization of 1,3-dioxan-2-one (trimethylene carbonate) (TMC) monomer, initiated by the functional groups of chitosan in the pres...
Article
The detection of heavy metals, such as Hg²⁺ and Fe³⁺, is of great significance. In this work, fluorescent small-molecule BODIPY (BY-3) bearing CC group was synthesized firstly. And then, the chitosan-based polymer sensor CY-1 was synthesized through the spontaneous NH2/C≡C click reaction. The synthesized CY-1 can effectively bind and recognize Hg²⁺...
Article
Vitamin B6 is an essential micronutrient in the mammalian diet, with role of coenzyme and synergistic effect with some antibiotics and antitumor drugs. Based on these, we hypothesized that its use for the preparation of hydrogels can yield multifunctional biomaterials suitable for in vivo applications. To this aim, chitosan was reacted with the act...
Article
Fe³⁺ and Fe²⁺ are common metal ions in natural water environments and creatures. The development of water-soluble fluorescent sensors for detecting Fe²⁺/Fe³⁺ ions was of great significance. In this work, two kinds of boron fluoride dipyrrole (BODIPY) fluorescent small-molecules were synthesized firstly. One of the small molecules contains a thioest...
Article
The paper reports hydrogels prepared from chitooligosaccharides with different polymerization degrees (14 to 51), by crosslinking with 2-formylphenylboronicacid in three molar ratios of their functionalities. The structural, morphological and supramolecular characterization confirmed a hydrogelation mechanism based on self-assembling of newly forme...
Article
2,4,6-trinitrophenol (TNP) and 2,4-dinitrophenylhydrazine (DNH) are harmful to the environment and human beings. Trace detection of TNP and DNH is worth of developing facile methods. In this work, cellulose powder and filter paper based fluorescence sensor are synthesized. Firstly, NH2CH2CH2- was introduced into cellulose through etherification rea...
Article
Full-text available
The paper aimed to prepare imino-chitosan fibers by the imination reaction in a heterogenous system, targeting the improvement of anti-pathogenic activity. To this end, porous neat chitosan fibers were prepared by electrospinning of the polyethylene glycol/chitosan blend, followed by polyethylene glycol removal. Imination of the neat chitosan fiber...
Article
The paper reports the preparation and characterization of a series of functionalized chitosan nanofibers designed for tissue engineering. Their functionalization was done by imination with two aldehydes with complementary bioactivity, one possessing antimicrobial activity and the other one having potential to enhance it by improving the cell permea...
Article
Chitosan is a biopolymer originating from renewable resources, with great properties which make it an attractive candidate for plenty of applications of contemporary interest. By manufacturing chitosan into nanofibers using the electrospinning method, its potential is amplified due to the enhancement of the active surface and the low preparation co...
Article
Full-text available
Introduction Cancer is a big challenge of the 21 century, whose defeat requires efficient antitumor drugs. Objectives The paper aims to investigate the synergistic effect of two structural building blocks, phenothiazine and poly(ethylene glycol), towards efficient antitumor drugs. Methods Two PEGylated phenothiazine derivatives were synthetized b...
Article
Chitosan has been widely used due to its biodegradable, cost-effective and environmentally friendly properties. Modification of chitosan attracts much attention as promising methods to detect and remove organic and inorganic pollutants. In this work, chitosan-based macromolecular probes were designed and synthesized. The probes can detect Fe³⁺ in t...
Chapter
Chitosan based hydrogels are a class of materials intense investigated for real life applications. This is because their main component, chitosan, is a naturally originated biopolymer, sustainable, biocompatible, biodegradable and possessing many other useful biologic properties. The traditional pathways of chitosan hydrogelation, i.e. physical and...
Article
Full-text available
A series of new azomethine dimers was synthesized by the condensation reaction of flexible bis-benzaldehydes with four aromatic amines containing phenyl, naphthyl, anthracene and pyrene groups. Their right structure was confirmed by FTIR and 1H-NMR spectroscopy and their thermal properties were investigated by thermogravimetric analysis, differenti...
Article
Full-text available
The aim of the study was to create a mathematical model useful for monitoring the release of bioactive aldehydes covalently bonded to the chitosan by reversible imine linkage, considered as a polymer–drug system. For this purpose, two hydrogels were prepared by the acid condensation reaction of chitosan with the antifungal 2-formyl-phenyl-boronic a...
Article
The development of water-soluble polymer dyes is of great practical and scientific significance. In this article, small fluorescent molecule boron-dipyrromethene (BODIPY) bearing C=C bond was synthesized first. And then, via Suzuki reaction, recognition groups were introduced into the 2, 6 positions of BODIPY. Thus polymerizable fluorescent monomer...
Article
Multi-component polymer (MCP) is a kind of polymer that incorporates multiple components in the main chain or pendant group and has special functions. In this work, small-molecule fluorescent boron-dipyrromethene (BODIPY)...
Article
Full-text available
This paper reports new formulations based on chitosan, citral, and diclofenac sodium salt (DCF). The central idea was to encapsulate an anionic drug into a polycationic hydrogel matrix in order to increase the intermolecular forces between them and thus to ensure slower drug release, while citral was used as a penetration enhancer to assure efficie...
Article
The quaternary ammonium salts of chitosan are water soluble derivatives which keep the promise for real life applications in a large realm of biomedical fields, such as antimicrobial products, gene therapy, drug delivery, wound healing, tissue engineering and cosmetics. The increased potential for such applications is gained by a beneficial combina...
Article
A series of five eco-friendly PDLC composite films based on cholesteryl acetate liquid crystal and chitosan were obtained and characterized. The resulted composites were evaluated in terms of structure and morphology by FTIR and RAMAN spectroscopy and scanning electron microscopy, while their thermotropic behavior was evaluated by polarized optical...
Article
The aim of the paper was to investigate the ability of an eco-friendly luminescent xerogel prepared by chitosan crosslinking with a phenothiazine luminogen to detect and remove heavy metals. Its ability to give a divergent morphological and optical response towards fifteen environmental relevant metals was investigated by naked eye and UV lamp, flu...
Article
The paper reports a series of three new PEGylated phenothiazine derivatives which keep the potential of valuable building blocks for preparing eco-materials addressed to a large realm of fields, from bio-medicine to opto-electronics. They were synthetized by connecting the hydrophilic poly(ethylene glycol) to the hydrophobic phenothiazine via an et...
Article
The present paper focuses on the synthesis and characterization of new hydrogels and drug delivery systems, designed for local therapy. The hydrogels were obtained by reacting PEG-ylated chitosan derivatives with citral in different molar ratios of their functionalities. The drug delivery systems were obtained by the in situ hydrogelation of PEG-yl...
Article
The objective of this paper was to investigate the new formulations based on salicyl-imine-chitosan hydrogels as potential controlled drug release systems. They were prepared by in situ hydrogelation of chitosan with salicylaldehyde in the presence of diclofenac sodium salt (DCF) as model drug. FTIR, X-ray Spectroscopy, POM and SEM techniques were...
Article
A series of binary phenothiazine based co-crystals were designed with the aim to reach materials with improved quantum efficiency in solid state. To this end, a host dibromine functionalized phenothiazine was mixed with a guest formyl based phenothiazine in various molar ratios, from 1:1 up to 1:9, to form single crystals and thin films as well. Si...
Article
Full-text available
In this work, SiO2 microspheres were first prepared by a conventional Stöber method and then etched by NaOH solution to obtain porous ones. By tuning the degree of etching, specific surface area of SiO2 microspheres could be controlled. Then, small fluorescent molecules are synthesized and incorporated onto the surface and/or pores of the SiO2 via...
Article
Full-text available
The study aims to develop an edible bioactive coating. [...]
Article
The paper deals with the design and investigation of the morphology, in vitro drug release and biocompatibility of some new formulations based on polyvinyl alcohol boric acid (PVAB) and diclofenac sodium salt (DCF), with the aim to explore the ability of PVAB to act as a matrix for controlled drug delivery systems. A series of three formulations wa...
Article
Full-text available
An alternant poly(dihexyl fluorene-co diphenyl oxadiazole) has been synthetized by microwave-assisted oxidative polymerization. The structure has been confirmed by 1H-NMR and FTIR spectroscopies. Gel permeation chromatography indicated high molecular weight and low polydispersity index. DFT calculations suggested a complete separation of HOMO and L...
Conference Paper
Full-text available
Co2 capture and sequestration and finally reduction is main aim of the research , this contribution shows two different approaches
Article
Nitroaromatic compounds, especially 2, 4, 6-trinitrophenol, have strong biological toxicity and explosive risks, so the detection of 2, 4, 6-trinitrophenol exhibit importantly practical and scientific significance. In this work, three fluorescence functionalized chitosan CNS 3, CNS 4 and CNS 5 were prepared using chitosan as matrix. When 2, 4, 6-tr...
Article
The goal of the paper was to design a new pathway towards eco-materials suitable for CO2 capture, by functionalization of nanoporous chitosan fibers with monoaldehydes via imination. To this end, nanoporous chitosan fibers were prepared by electrospinning and further reacted with furfural. Their morphology was investigated by SEM and AFM microscopi...
Article
The paper reports new soil conditioner systems obtained by in situ hydrogelation of chitosan with salicylaldehyde in the presence of urea fertilizer, designed to address both fertilization and water retention of the soil. The new systems were structural, supramolecular and morphological characterized by FTIR spectroscopy, XRD diffraction, POM and S...
Article
Detection of heavy metals with high sensitivity and selectivity is of vital importance. This work deals with the synthesis of small molecular chemosensors and the fabrication of corresponding macromolecular fluorescent chemosensors. Boron dipyrrole methane (BODIPY) derived chemosensors, BE and BB were designed and synthesized first. Then, they were...
Article
Dynamic constitutional chemistry has been used to design nonviral vectors for gene transfection. Their design has been thought in order to fulfill ab initio the main requirements for gene therapy. As building blocks were used hyperbranched PEI as hydrophilic part and benzentrialdehyde and a diamine linear siloxane as hydrophobic part, connected thr...
Article
The paper focuses on the synthesis and characterization of new drug delivery systems for local therapy. They were prepared by in situ hydrogelation of chitosan biopolymer with nitrosalicylaldehyde in the presence of a model drug, varying the crosslinking density. The structural, supramolecular and morphological characteristics of the systems were s...
Article
Polymer dispersed liquid crystal (PDLC) composites were prepared by the encapsulation of cholesteryl acetate (L-ChAc) in polyvinyl alcohol boric acid (PVAB) by microemulsion technique. The supramolecular and morphological peculiarities of the resulted composites were analyzed by polarized optical microscopy, fluorescence microscopy and scanning ele...
Article
Full-text available
A series of drug delivery systems were prepared by chitosan hydrogelation with citral in the presence of an antineoplastic drug: 5-fluorouracil. The dynamic covalent chemistry of the imine linkage allowed the obtaining of supramolecular tridimensional architectures in which the drug has been homogenously dispersed. Fourier-transform infrared spectr...
Article
The paper focuses on the preparation of phenothiazine based nanoparticles, both in liquid and solid states, by reprecipitation in water and solvent induced phase separation respectively. Polymethylmethacrylate was used as an inert matrix and polyfluorene as a luminescent matrix. The morphological features of the nanoparticles were investigated by d...
Article
A series of chiral hydrogels was prepared from a homogeneous mixture of chitosan and betulinic aldehyde in different molar ratios, under the effect of ultrasound. The hydrogelation mechanism has been investigated by FTIR and CD spectroscopy, wide angle X-ray diffraction and polarized light microscopy. The morphology of hydrogels was examined by SEM...
Article
Full-text available
Pure organic luminescent hydrogels were synthesised using condensation reaction of amino groups of chitosan with a photoactive aldehyde bearing phenothiazine moiety. The hydrogels were structurally and supramolecularly characterized by FTIR and 1H-NMR spectroscopy, X-ray diffraction and polarized light microscopy. It was concluded that hydrogelatio...
Article
A series of hydrogels based on chitosan polyamine and nitrosalicylaldehyde were prepared via dynamic covalent chemistry (DCC), by imination and transimination reactions towards ordered clusters which play the role of crosslinking nodes of the chitosan network. The hydrogelation mechanism has been proved through NMR and FTIR spectroscopy, X-ray diff...
Article
A series of poly(azomethine-phenothiazine)s was synthesized by using the reaction of 10-methyl-phenothiazine-3,7-dicarbaldehyde with diamines containing fluorene chromophore or polyethylene glycol (PEG) flexible spacer. The polymers were structurally characterized by ¹H-NMR and FTIR spectral techniques, elemental analysis and wide angle X-ray diffr...
Article
A series of seven low molecular weight compounds containing triazole, pyridine-N-oxide and one substituted aromatic ring linked together by heteroatom containing spacers was synthesized by click chemistry reaction. The compounds were structurally characterized by FTIR, NMR, as well as single crystal X-ray diffraction. Their morphologic, thermotropi...
Article
The paper focusses on the synthesis of novel hydrogels by joining natural biodegradable compounds with the aim to achieve biocompatible materials for bio related applications. The hydrogels were prepared from chitosan and citral by constitutional dynamic chemistry, incorporating both molecular and supramolecular dynamic features. The hydrophobic fl...
Article
Hydrogels based on chitosan and salicyladehyde were obtained by dynamic covalent chemistry. The unusual chitosan gelling in the presence of the monoaldehyde has been deciphered following and correlating data of NMR, FTIR, single crystal and wide angle XRD, POM and optical measurements. Of significant importance in understanding the crosslinking fea...
Article
Full-text available
Chitosan based hydrogels are a class of cross-linked materials intensely studied for their biomedical, industrial and environmental application, but their biomedical use is limited because of the toxicity of different organic crosslinkers. To overcome this disadvantage, a new strategy to produce supramolecular chitosan hydrogels using low molecular...
Article
Novel phenoxazine-based imine dyes having a donor-acceptor-donor (D-A-D) topology were designed, synthesized and thoroughly investigated with regard to their thermotropic, photo-physical and electrochemical behavior. The hexyl-substituted phenoxazine was selected as donor moiety and diphenyl-1,3,4-oxadiazole or fluorene-containing moieties were emp...
Article
A series of nine dyes based on electron-donating phenothiazine core functionalized with various carbonyl containing electron-withdrawing moieties as primary end group and with or without bromine as a second heavy end group were designed and synthesized to generate variable supramolecular architectures with distinct thermotropic, photophysical, and...
Article
Polymer dispersed liquid crystal (PDLC) systems based on a smectic liquid crystal embedded in polyvinylalcohol-boric acid (PVAB) as biocompatible carrying matrix were prepared and characterised. The smectic liquid crystal contains biologically friendly structural blocks and was designed to have a direct isotropic–smectic transition and a mesophase...
Article
The paper presents the obtaining of a phenothiazine based blue light emitter via an efficient oxidation process of a phenothiazine based aldehyde to the corresponding carboxylic acid in basic media - a quite unusual synthetic route, evidenced in the approach of Horner-Wadsworth-Emmons coupling reaction. The structure of the reagent and correspondin...
Article
The design of performant nonviral vectors for efficient cellular DNA uptake represents a grand challenge. The variability of DNA targets and of the transfected cells limits the discovery of highly active nonviral vectors. Dynamic constitutional strategy presented here, combining easy synthesis and rapid screening, enables the selection of dynameric...
Article
The electrochemical deposition method has been used as an appropriate tool for preparing ultrathin films of fluorene-based polymers for applications in electroluminescent devices. Thus, for the first time, electropolymerization by consecutive multisweep cyclic voltammetry (CV) of 4,4′-(9-fluorenylidene)-dianiline (FDA) in dichloromethane solution c...
Article
A new series of thermotropic polyazomethines (PAMs) containing flexible spacers in the main chain and side methoxy groups on the mesogenic core has been synthesised by solution polycondensation reaction of o-dianisidine with α,ω-bis(4-formylphenoxy)-alkanes. A model compound was also synthesised by condensation reaction of o-dianisidine with p-buto...
Article
Organic–inorganic hybrid materials have been obtained by impregnating a mesomorphic polyazomethine into a porous inorganic matrix of zinc oxide (ZnO), tin dioxide (SnO2), or mixed ZnO/SnO2. The porous inorganic matrix has been obtained by magnetron sputtering technique and proved a very high crystallinity degree. The resulting hybrid materials were...
Article
Full-text available
Fifteen azomethine compounds based on different rigid cores and soft aliphatic tails have been designed and synthesized to generate variable supramolecular architectures with distinct thermotropic, photophysical and electrochemical properties. Ten out of the fifteen imines were grown as single crystals and their molecular structures and supramolecu...
Article
The paper reports the preparation of twelve imino-chitosan biopolymer films by acid condensation of the amino groups of chitosan with various aldehydes, in aqueous medium, followed by slow water removal. FTIR spectroscopy has shown drastic conformation changes of chitosan macromolecular chains - from a stiff coil to a straight one, while wide angle...
Article
Aggregation-induced emission (AIE) low molecular weight compounds based on triazoles, phenothiazine and pyridine-N-oxide units bonded by short flexible chains have been obtained by a “click” chemistry reaction. The photophysical properties were explored by UV-vis and photoluminescence spectroscopy in solution, water suspension, and amorphous and cr...
Article
Polymer-dispersed liquid crystal (PDLC) systems based on polysulfone as carrying matrix and 4-cyano-4ʹ- pentylbiphenyl (5CB) liquid crystal (LC) were obtained as thin transparent films. The PDLC films were prepared by solvent- and thermally induced phase separation methods, with various compositions in the two components. Information on the phase s...
Article
A smectogen liquid crystal based on benzoate units has been synthesized and structurally characterized by FTIR and 1H NMR spectroscopy. Besides, its structure and supramolecular arrangement in the crystalline state was demonstrated by single crystal X-ray diffraction measurements. The thermotropic behaviour, monitored by differential scanning calor...
Article
Full-text available
This paper presents the synthesis of some Schiff bases with potential antimicrobial activity. A new ligand was synthetized through the condensation reaction of aniline with various aldehydes: benzaldehyde, salicylic aldehyde, p-hydroxy-benzaldehyde and vanillin. The chemical structure was confirmed by 1H NMR and IR spectroscopy. The antimicrobial a...
Article
New hybrid guest/host composite films obtained by dispersing a light-emitting azomethine dimer into three different matrix polymers have been studied. Poly(methyl methacrylate) (PMMA), UDEL polysulfone (PSU) and chitosan were chosen as host matrix. Differential scanning calorimetry, polarized light microscopy, scanning electron microscopy and atomi...
Article
A polymer dispersed liquid crystal composite (PDLC) based on polyvinyl alcohol boric acid (PVAB) as polymer matrix and 4-cyano-40-penthylbiphenyl (5CB) as liquid crystal has been prepared by an encapsulation method. PVAB was used as a polymer matrix for the first time. Polarized light microscopy, scanning electron microscopy, differential scanning...
Article
An investigation of the constitutional adaptive gelation process of chitosan/cinnamaldehyde (C/Cy) dynagels is reported. These gels generate timely variant macroscopic organization across extended scales. In the first stage, imine-bond formation takes place “in-water” and generates low-ordered hydrogels. The progressive formation of imine bonds fur...