project tytle: "interdisciplinary research on multifunctional hybrid particles for...
TRANSCRIPT
Project tytle:"Interdisciplinary research on multifunctional
hybrid particles for biorequirements”acronim: INTERBIORES
Contract no. 211/2012
Project Cod: PN-II-PT-PCCA-
2011-3.2-0428 – Program PN II –
Partnerships Priority Areas -
Applied Research Projects –
Type 2
Contracting Authority: Executive Unit for Financing HigherEducation, Research Development and Innovation (UEFISCDI)Contractor: "Petru Poni" Institute of Macromolecular Chemistry,Iasi
Duration of project: 02.07.2012 – 02.07.2015 The total value of the contract 3.323.334 lei From the source of funding:
Source 1 - The state budget: 2.950.000 lei
Source 2 - from other sources
(Net financing) 373.334 lei Project Director: CS I Dr. Aurica P. Chiriac
Members:
“Petru Poni” Institute for Macromolecular Chemistry – Iasi
- Project Coordinator
Project Director: Dr. Chiriac P. Aurica “Gr. T. Popa” Medicine and Pharmacy University Iasi –
UMF - Partner 1
Team leader: Dr. Verestiuc Liliana Research and Development National Institute of Technical
Physics Iasi Iaşi - Partner 2
Team leader: Dr. Chiriac Horia SC REZISTOTERM SRL Partner 3
Team leader: Dr. Chiriac Mihai
Abstract:
The project with multi-disciplinary character is focused on analysis and solving from the physical, chemical and biochemical viewpoint the design and technology of novel systems, based on antioxidants-loaded core-shell magnetic nanocomposites deposited onto the stent surface. Novel formulation methods based on the use of biocompatible polymers will be developed and applied to create a family of magnetic nanoparticles (MNPs) further characterized as a platform for magnetically guided delivery of therapeutics. The selected polymers will undergo physical (forming of interpolymer complexes by physical interactions) and chemical (functionalization, derivatization, crosslinking, reactive mixing) modifications in order to obtain stable multifunctional nanosystems. The key features of the new target delivery systems will be investigated, including in vitro bioactive compounds activity, capacity to protect the antioxidants from proteolysis, as well as the capacity of the magnetic guidance and retrieval. The project includes aspects like toxicology, biocompatibility of the nanodevices, and also efficacy and biodistribution of the system. The studies are doing to the facts that a major problem associated with target delivery is the inability to deliver pharmaceuticals to a specific site of the body without causing nonspecific toxicity. The bioproducts loaded magnetic nanoparticles have several advantages such as: small particle size, large surface area, magnetic response, biocompatibility and non-toxicity and are directed with external magnets to the right site, and requires smaller dosage because of targeting, with no side effects.
One of the most innovative aspects of this proposal is the use of functionalized magnetic nanoparticles with antioxidative biomolecules deposited onto the stent surface to realize a drug-eluting-stent type for bio-requirements. The new stent device will functioning as a delivery platform. At the same time, the prepared MNPs will represent a particularly appropriate tool based on their ability to be simultaneously functionalized and guided by an external magnetic field, the presence of the antioxidative biomolecules would be an additional benefit.
To conclude, the purpose of the multi-disciplinary character project is to realize target delivery systems based on hybrid bio-nano-composites with improved magnetic performance of the nanoparticles and maximized therapeutic potential of the drug eluting/retrieval stents by the loaded antioxidative biomolecules layered on the stent surface. In addition, the design of the nanoparticles will include the improvement of the monodispersity, colloidal stability and functionality. Also, further engineering of these nanoparticles and of their formulation as hybrid systems for target delivery will allow improving their bioselectivity and bioefficiency.
Concept and objectives:
The project with multi-disciplinary character is focused on analysis and solving from the physical, chemical and biochemical viewpoint the design and technology for the stents achievement with drug delivery possibilities, based on antioxidants-loaded core-shell magnetic nanocomposites deposited onto the stent surface.
The market for stents is, in many ways, still emerging. While coronary stents have been on the commercial market in one form or another for several years, the technologies and materials used to create the devices are improving every day. In addition, innovative technology is bringing new classes of devices (e.g., fully degradable stents) to market, technologies that grow the market and even expand means of diagnosis and therapy stent to new patient populations in some cases.
One of the most innovative aspects of this proposal is the use of functionalized magnetic nanoparticles with antioxidative biomolecules deposited onto the stent surface to realize stent devices type for bio-requirements. Thus the new stent device will function as a delivery platform. At the same time, the prepared MNPs will represent a particularly appropriate tool based on their ability to be simultaneously functionalized and guided and/or removed by an external magnetic field owing to the magnetic NPs inclusion, meanwhile the presence of the antioxidative biomolecules would be the additional benefit. As it is well known stents are scaffoldings, usually cylindrical or tubular in shape, which function to physically hold open and, if desired, to expand the wall of the vessel. Typically stents are capable of being compressed, so that they may be inserted through small cavities via catheters, and then expanded to a larger diameter once they are at the desired location. Although stents are significant innovations in the treatment of occluded vessels, there remains a need for administering therapeutic substances to the treatment site. Systemic administration of the therapeutic substance often produces adverse or toxic side effects for the patient. Local delivery of therapeutic substances, by contrast, provides a smaller overall dosage that is concentrated at a specific treatment site. Local delivery can produce fewer side effects and achieve more effective results. In this context novel formulation based on biocompatible polymers will be developed and applied to create a family of antioxidant magnetic nanoparticles (MNPs) for covering the stent surfaces further characterized as a platform for magnetically guided and delivery of therapeutics. The selected polymers will undergo physical (forming of interpolymer complexes by physical interactions) and chemical (functionalization, derivatization, crosslinking, reactive mixing) modifications in order to obtain stable multifunctional nanosystems. The key features of the new target delivery systems will be investigated, including in vitro bioactive compounds activity, capacity to protect the antioxidants from proteolysis, as well as the capacity of the magnetic guidance, retrieval and remove. The project includes aspects like toxicology, biocompatibility of the nanodevices, and also efficacy and biodistribution of the system. In addition, the design of the nanoparticles will include the improvement of the monodispersity, colloidal stability and functionality. Also, further engineering of these nanoparticles and of their formulation as hybrid systems for target delivery will allow improving their bioselectivity and bioefficiency.
Stage I/2012 – the obtained results:
In accordance with the plan of the project "Interdisciplinary research on multi-functional hybrid particles for bio-requirements", the stage I/2012 has the objectives:
(I) magnetic composites preparation and (II) their physical – chemical evaluation, which were fulfilled by specific activities : - the obtaining of magnetic nanoparticles (NPs) with linking capacity and antioxidant enzymes transport; - the surface modification of magnetic NPs with polymeric structures, as basis for antioxidant hybrid materials; - the characterization of the magnetic composites with the aim of association with antioxidant enzymes and the estimation of the physical-chemical theoretical and experimental conditions necessary for their realization, and the dissemination of the results by national and international symposia communications, publications in the ISI quoted journals or indexed in international databases.
The conducted studies have resulted in: (I) Synthesis and characterization of polymeric matrices, respectively: (1) poly(2-hidroxyethyl methacrilate-co-3,9-divinyl-2,4,8,10-
tetraoxaspiro[5.5]undecan-co-glicidil methacrylate) ternar copolymer (synthesized by radical copolymerization in aqueous dispersion); 2) poly(dimethyl acrylamide-co-3,9-divinyl-2,4,8,10-tetraoxaspiro [5.5]undecan-co-itaconic acid) ternar copolymer (synthesized by
radical copolymerization in dimethyl acetamide solution); (3) poly(2-hydroxyethyl methacylate-co-3,9-divinyl-2,4,8,10-tetraoxaspiro [5.5]undecan –coacrylamide)(synthesized by radical
copolymerization in dimethyl acetamide solution); (4) 6 variants of bloc copolymers based on poly(succinimide)-b-poly(ethylene glycol)(PEG) (synthesized by copolycondensation in
dimethyl formamide in the presence of Mn(CH3COO)2.2H2O as catalyst ), PEG having different molecular weights, such as : 2000, 3000, 4000, 10000, 20000 and 35000;
(5) one grafted polymeric structure based on carboxymethyl starch-g-poly(lactic acid); (II) The preparation of hybrid structures with magnetic characteristics by using the realized polymeric matrices; (III) Testing activities of the polymeric matrices and hybrid structures for coupling of the antioxidant enzymes, in course.
In the context of the dissemination activity of the results by communications at national and international symposia, by publications in the ISI quoted journals or indexed in international databases, there were presented:
(a) Three communications at 5th International Conference “Biomaterials. Tissue Engineering and Medical Devices” BiomMedD’2012, Constanta, 29 August – 1 September 2012, respectively:
Streptavidin-Biofunctionalized Magnetic Particles for Blood Contacting Applications; V. Bălan, M.I. Popa, A.P. Chiriac, I. Neamtu, L.E. Nita, M.T. Nistor, M. Butnaru, L. Verestiuc
Bioactive Hybrid Scaffolds in Regenerative Medicine and Tissue Engineering; M.T. Nistor, C. Zgardan, C. Vasile, L.E. Nita, A. Chiriac
Assembly Design and Characterization of an Innovative Modulated Drug Delivery System; L. Nita, M. Nistor, N. Tudorachi, I. Neamtu, A. Chiriac
(b) One communication „Determination of the kinetic parameters and analysis of gases released by thermal decomposition of CMS-g-PLA copolymer” at XXXII National Chemical Conference Rm Valcea, October 2012, and
( c ) One paper accepted for publication in Industrial & Engineering Chemistry Research (IF = 2.237): “Thermal degradation of carboxymethyl starch-g-poly(lactic acid) copolymer by TG-FTIR-MS analysis”, authors Nita Tudorachi, Rodica Lipsa, Fanica Mustata.
Stage II/2013:
In accordance with the plan of the project „Interdisciplinary research on multi-functional hybrid particles for bio-requirements”, the phase II/2013 had as objectives (I) Magnetic composites synthesis and (II) Physical-chemical evaluation (phase I/2012 continuation). The objectives were carried out through and finalized by specific activities, such as:
- the obtaining of magnetic nanoparticles (NPs) with linking capacity and antioxidant enzymes transport;- experimental development for magnetic NPs surface modification with the aim of obtaining molecular adapted bio-structures, as
basis for new hybrid materials;- the evaluation of antioxidant enzymes, significant for biological structures;- magnetic NPs bio-functionalization with biological structures for the nanometric level control of the biological and biochemical
processes;- experimental development for the obtaining of bio-functionalized magnetic NPs;- magnetic composites characterization in association with antioxidant enzymes for the estimation of the experimental and theoretical
physical-chemical conditions necessary for their preparation;- elucidation and characterization of the surface properties of the particles, associated with antioxidant enzymes coupling reactions
and results interpretation for subsequent studies of targeted delivery and controlled release;- dissemination of the results by communications at national and international symposia, by publications in the ISI quoted journals or
indexed in international databases.- The dissemination of the results by communications at national and international symposia, by publications in the ISI quoted
journals or indexed in international databases, materialized as it follows:
The obtained results:
Published papers:
- Characterization of the semi-interpenetrated network based on collagen and poly(N-isopropyl acrylamide-co-diethylene glycoldiacrylate). Authors: MT Nistor, A.P. Chiriac, LE Nita, C Vasile. Int J Pharmaceutics 452 (2013) 92– 101; IF=3.458.
- Multilayered structure based on poly(N,N-dimethyl-acrylamide-co-3,9-divinyl-2,4,8,10-tetraoxaspiro (5.5) undecane) prepared in a multiphase gelation process. Authors: AP Chiriac, LE Nita, MT Nistor, L Tartau. Int J Pharmaceutics 456 (2013) 21– 30; IF=3.458.
- Obtaining of new magnetic nanocomposites based on modified polysaccharide. Authors: NTudorachi, AP Chiriac, Carbohydrate Polymers 98 (2013) 451– 459; IF=3.479.
- Upon the Delivery Properties of a Polymeric System Based on Poly(2-Hydroxyethyl Methacrylate) Prepared with Protective Colloids. Authors: LE Nita, AP Chiriac, M Nistor, TBudtova. J Biom Nanobiotechnol 4(2013), 357-364; ISSN Online: 2158-7043.
- Upon the Developments of Drug-Eluting Stents in the Treatment of Coronary Lesions. Authors: A.Diaconu, V Balan, AP Chiriac. Recent Patents on Materials Science 6(2013) 229-237; ISSN:1874-4648.
- Semi-interpenetrated Network with Improved Sensitivity Based on Poly(N-Isopropylacrylamide) and Poly(aspartic acid). Authors: MT Nistor, AP Chiriac, LE Nita, INeamtu, CVasile. Polym Eng Sci 53(2013) 2345-2352; IF=1.243.
- Poly(N,N-dimethylacrylamide-co-3,9-divinyl-2,4,8,10-tetraoxaspiro(5.5)undecane) synthesis as matrix ensuring intramolecular strategies for further coupling applications. Authors: AP Chiriac, MT Nistor, LE Nita, I Neamtu. Rev. Roum. Chim. 58(2013)(2-3), 129-136; IF-0.331.
The obtained results:
- Hydrogel based on poly(N,N-dimethylacrylamide-co-3,9-divinyl-2,4,8,10-tetraoxaspiro(5.5)undecane) with dual sensitive behavior. Synthesis and characterization. Authors: LE Nita, AP Chiriac, MT Nistor, I Neamtu. Rev. Roum. Chim., 2013, 58(2-3), 137-143; IF-0.331.
- Poly(acrylic acid)/ poly(ethylene glycol) nanoparticles designed for ophthalmic drug delivery. Authors: A.M. Vasi, M.I.Popa, E.C.Tanase, M. Butnaru, L. Verestiuc, agreed to be published in J. Pharm. Sci.; IF=3.13.
Book Chapters :- Chapter 3. Hybrid Sensitive Hydrogels for Medical Applications. MT Nistor, C Vasile, AP Chiriac, A Rusu, C
Zgardan, LE Nita, I Neamtu. In: Polymer materials with smart properties. Ed. M Bercea. Nova Science Publ. New York 2013, 67 – 89.
- Chapter 8. Sol-Gel Technique Implemented for Biomedical Applications. LENita, AP Chiriac, I Neamtu. 189-204. In: Polymer materials with smart properties. Ed. M Bercea. Nova Science Publ. New York 2013, 189 – 204.
Published papers in Proceedings:- Functionalized superparamagnetic nanoparticles as versatile carriers for targeted antioxidant enzyme therapy .
Authors: V.Balan, M. Butnaru, O. Bredetean, L. Profire, G. Lupascu, A.P.Chiriac, L.E. Nita¸ I. Neamtu, L.Verestiuc Proceedings of the 4th ed. of E-Health and Bioengineering Conference-EHB 2013, Iasi, Romania.
- Biomimetic composites based on calcium phosphates and chitosan - hyaluronic acid with potential application in bone tissue engineering. Authors: F.D.Ivan, A.Marian, C. E. Tanase, M. Butnaru, L. Vereştiuc, Bioceramics 25, Key Engineering Materials, 587, 191-196.
The obtained results:
Communications at scientific meetings:- Functionalized superparamagnetic nanoparticles as versatile carriers for targeted antioxidant enzyme therapy.
V. Balan, M. Butnaru, O. Bredetean, L. Profire, G. Lupascu, A.P.Chiriac, L.E. Nita¸ I. Neamtu, L.Verestiuc, 4th IEEE International Conference on E-Health And Bioengineering - EHB 2013, Iaşi, Romania, November 21st-23rd, 2013.
- Biomimetic composites based on calcium phosphates and chitosan - hyaluronic acid with potential application in bone tissue engineering. 25th Symposium and Annual Meeting of the International Society for Ceramics in Medicine; Bucharest, Romania November 07-10th 2013; Autori: F.D.Ivan, A.Marian, C. E. Tanase, M. Butnaru, L. Vereştiuc, Bioceramics 25, Key Engineering Materials, 587, 191-196.
Poster at scientific meetings:- Process for magnetic composites synthesis. Authors: AP Chiriac, LE Nita, INeamtu, MT Nistor. The 17th
International Salon of Research, Innovation and Technological Transfer “Inventica 2013” 19 – 21 st June 2013 Iasi – Romania.
- Hybrid Structures for Bioapplications. Authors: AP Chiriac, LE Nita, INeamtu, MT Nistor. National Innovation Salon CHIM-INVENT, 3 – 5 July 2013, Iasi Romania.
Registered patent application: - Magnetic composite synthesis process. Authors : A.P. Chiriac, L.E. Nita, I. Neamtu, N.Tudorachi, A. Diaconu,
V. Balan, C. Munteanu. Patent application No. A 00833/13.11.2013.
Stage III/2014: Plan and activities
Physico-chemical evaluation (continuation from 2013) Bio-chemical evaluation; Methods for toxicological evaluation of NPs for providing fundamental knowledge on their
design and testing as targeted delivery systems. Integration of bio-magnetic systems
- Activity 2.7
Characterization of magnetic composites in combination with antioxidant enzymes to determine the
experimental conditions to achieve them - continuing in 2012 and 2013
- Activity 2.8
The elucidation and characterization of surface properties of the particles associated with the coupling reaction
of the antioxidant enzyme for further studies of release (activity continuation from 2012 and 2013)
- Activity 2.9
Determination of the initiation reactions of self-assembling mechanisms for hybrid materials preparation - Part
- Activity 2.10
Conceptual design of coupling system between the magnetic composite and the antioxidant enzyme -Part I
- Activity 2.11
Dissemination of results through communications at national and international symposia, publications in
journals
Stage III/2014: Plan and activities
- Activity 3.1
Establish procedures for the preparation and characterization of new materials
- Activity 3.2
Dissemination of results through communications at national and international symposia, publications in
journals ISI or indexed in international databases
- Activity 3.3
Testing biomagnetic self-assembled hybrid materials with antioxidant characteristics - Part I
- Activity 3.4
Testing and evaluation of hybrid systems - Part I
Preparation of the magnetic composite in situ, with magnetite encapsulated in the matrix of poly (maleic anhydride-co-3,9-divinyl-2,4,8,10-tetraoxaspiro [5.5] undecane) (PMA-co-U) during functionalization of the copolymer with meso-erythritol :
Copolymer structure functionalized with erythritol, and the resulting magnetic composite were characterized by specific methods;
Hybrid structures were loaded with antioxidant enzymes; The enzymatic activity of the functionalized magnetic composites
was performed.
Poly(maleic anhydride-co-3, 9-divinyl-2, 4, 8, 10-tetraoxaspiro (5.5) undecane)
Magnetite
Erythritol
Magnetite
Magnetite
Erythritol
Erythritol
Erythritol
Magnetite
CH
CH2 O
O O
O
CH
CHO O
OH
OH
OH
O
OH
OH
OCH2
CH
O
O
O
CH
CH
O
O
O
O
O O
CH
CH2
O
O
O
O
O
OH
OH
OH
O
CH2
CH
O
O
O
OCH2O
O
OH OH
OH
O
O
O
O
OHOH
OH
CH2
CH
O
O
O
O
O
O
O
OO
CH
CH2
O
CH2
CH
O
O
O
OCH2
O
O
O
CH
CH
O
O
O
O
O O
CH2
O
CH2
O
O
O
O
OH
OH
OCH
CH
O
O
O
CH
CH2
O
O
OH
OH
O CH CH2
O
OO
CH
O
O
OH
OH
O
O
O
CH
O
Fe
O
Fe
O
Fe
O
O
Fe
O
Fe
O
Fe
O
O
Fe
O
Fe
O
Fe
O
O
Fe
O
Fe
O
Fe
O
O
Fe
O
Fe
O
Fe
O
O
Fe
O
Fe
O
Fe
O
O
Fe
O
Fe
O
Fe
O
Poly(maleic anhydride-co-3, 9-divinyl-2, 4, 8, 10-tetraoxaspiro (5.5) undecane)
Magnetite
Erythritol
Magnetite
Magnetite
Erythritol
Erythritol
Erythritol
Magnetite
CH
CH2 O
O O
O
CH
CHO O
OH
OH
OH
O
OH
OH
OCH2
CH
O
O
O
CH
CH
O
O
O
O
O O
CH
CH2
O
O
O
O
O
OH
OH
OH
O
CH2
CH
O
O
O
OCH2O
O
OH OH
OH
O
O
O
O
OHOH
OH
CH2
CH
O
O
O
O
O
O
O
OO
CH
CH2
O
CH2
CH
O
O
O
OCH2
O
O
O
CH
CH
O
O
O
O
O O
CH2
O
CH2
O
O
O
O
OH
OH
OCH
CH
O
O
O
CH
CH2
O
O
OH
OH
O CH CH2
O
OO
CH
O
O
OH
OH
O
O
O
CH
O
Fe
O
Fe
O
Fe
O
O
Fe
O
Fe
O
Fe
O
O
Fe
O
Fe
O
Fe
O
O
Fe
O
Fe
O
Fe
O
O
Fe
O
Fe
O
Fe
O
O
Fe
O
Fe
O
Fe
O
O
Fe
O
Fe
O
Fe
O
-20000 -10000 0 10000 20000
-4
-2
0
2
4
-20000 -10000 0 10000 20000
-60
-40
-20
0
20
40
60
3
2
1
E
mu/
g
H [ Oe]
M, E
mu/
g
H, Oe
Preparation by in situ procedure of the magnetic composite, through encapsulation of magnetite in the copolymer matrix based on lactic acid (LA) and glycolic acid (GA) (PLGA):
PLGA copolymer was characterized from the
structural and functional view point;
The hybrid structure based on PLGA and magnetite
was characterized from the structural and functional
view point;
-20000 -10000 0 10000 20000-0.003
-0.002
-0.001
0.000
0.001
0.002
0.003
Mag
neti
zare
a, e
mu/
g
Camp magnetic, Qe
PLGA
PLGA copolymer structure
The in situ process of the hybrid structure PLGA / magnetite synthesis
Magnetization of PLGA copolymer and PLGA /magnetite composite performed in situ
Functionalization with model molecules and enzymes
- Functionalization of the polymer matrix based on poly
(maleic anhydride-co-3,9-divinyl-2,4,8,10-tetraoxaspiro
[5.5] undecane) and the magnetic composite was
carried out by molecule model (methionine) and
Enzymes;
- It assessed the enzymatic activity of functionalized
magnetic composites
FT-IR spectra of the polymer matrix before and after the functionalization, mediated by EDAC-reaction
FT-IR spectra of the functionalized magnetic composites
Conceptual design for coupling the magnetic antioxidant composite system at stent
- Schematic presentation for targeting the magnetic
nanoparticles (NMP) to a stent under the control of an
uniform magnetic field.
- The uniform magnetic field magnetizes NPM and stent
creates a region for capture the particle
Strategy for coating stents with hybrid magnetic structures prepared during this present stage
Conceptual design for coupling the magnetic antioxidant composite system at stent
Highlighting through optical
Microscopy the coating of
stents with the prepared
magnetic composite solution
Stent
Covered stent x100
Covered stent x500
The obtained results:
Published papers:1. Current concepts on cardiovascular stent devices; I. Neamtu, A. P. Chiriac, A. Diaconu, L.
E. Nita, V. Balan, M. T. Nistor; Mini-Reviews in Medicinal Chemistry, 14, 505-536 (2014). If=3.186
2. Semi-imprinting quercetin into poly[N,N-dimethylacrylamide-co-3,9-divinyl-2,4,8,10-tetraoxaspiro (5,5) undecane] network: Evaluation of the antioxidant character; A. P. Chiriac, L. E. Nita, L. Tartau, I. Neamtu, M. T. Nistor; Journal of Pharmaceutical Sciences, 103, 2338-2346 (2014). IF=3.007
3. Upon some multi-membrane hydrogels based on poly (N,N-dimethyl-acrylamide-co-3,9-divinyl-2,4,8,10-tetraoxaspiro (5.5) Undecane): preparation, characterization and in vivo tests, L. E. Nita, A. P. Chiriac, M. T. Nistor, L. Tartau; J. Mat. Sci.: Mat. in Med., 25 (7), (2014) 1757-1768, IF=2.379.
4. Upon Synthesis of Poly(N-isopropylacrylamide-co-2-dimethyl-aminoethyl methacrylate-co-itaconic acid) Copolymers as Matrix Ensuring Intramolecular Strategies for Further Coupling Applications; A. P. Chiriac, L. E. Nita, I. Neamtu, V. Balan, A. Diaconu; Journal of Research Updates in Polymer Science, 3 (1), 48-56 (2014). IF-0.0
The obtained results:
Communications at scientific meetings:1. A. Diaconu, A. P. Chiriac, L. E. Nita, N. Tudorachi, I. Neamtu, V. Balan; Upon synthesis of poly(maleic
anhydride-co-3, 9-divinyl-2, 4, 8, 10-tetraoxaspiro (5.5) undecane) copolymer with antioxidant character and possibilities for bioconjugation; communicated at 2nd International Conference on Chemical Engineering, Iasi , November 5-8 2014.
2. A. Diaconu, I. Neamtu, L. E. Nita, A. P. Chiriac, V. Balan, Poly(maleic anhydride-co-3, 9-divinyl-2, 4, 8, 10-tetraoxaspiro (5.5) undecane) copolymer-based magnetic composites: Potential vectors for remote-controlled bioactive substance release, 2nd International Conference on Chemical Engineering, Iasi , November 5-8 2014.
3. Tudorachi, A. P. Chiriac, G. Lisa, V. Balan, L. Nita, Magnetic nanocomposites PLGA/magnetite, “Alexandru Ioan Cuza” University Days, Faculty of Chemistry Conference, Iasi, 31 octombrie – 01 noiembrie 2014,
4. R. Lipsa, N. Tudorachi, A. Grigoras, C. Vasile, P. Gradinariu, A. P. Chiriac, F. Mustata, Poly(vinyl alcohol) copolymers biodegradation with Trichotecium roseum fungi “Alexandru Ioan Cuza” University Days, Faculty of Chemistry Conference, Iasi, 31 octombrie – 01 noiembrie 2014.
Registered patent application: Process for the synthesis of a magnetic composite ; A.P. Chiriac, L.E. Niţă, I. Neamtu, N. Tudorachi, A. Diaconu, V. Balan, A00808 from 29.10.2014.