Engenharia de Células e Tecidos

Transcription

1 Engenharia de Células e Tecidos Aplicações biomédicas LIPOSOMES IN GENE / CELL THERAPY by April 2008

2 Gene Therapy Cell Therapy h i / Use of genetic material (usually DNA) to manipulate a patient s cells for the treatment of an inherited or acquired disease. Infusion or transplantation of whole cells into a patient for the treatment of an inherited or acquired disease. April 2008

3 Safety Versatibility Low transfection efficiency and Different results obtained in vivo and in vitro Lipofection = Liposome + DNA = Lipoplexes April 2008

4 COMPOSITION PREPARATION LIPOSOMES CLASSIFICATION APPLICATIONS April 2008

5 COMPOSITION Polar head water Non-polar tail water April 2008

6 COMPOSITION Unilamellar Liposome Multilamellar Liposome April 2008

7 PREPARATION April 2008

8 Composition and application Structural parameters MLV (>0.5 μm) LUV (>100 nm) SUV ( nm) CLASSIFICATION Preparation method VET Vesicles obtained by Extrusion Technique DRV Dehydrated Rehidrated Vesicles April 2008

9 Composition and application Retained preferentially in liver and spleen Gene e Therap py PEG attached on the liposome surface Drug controled release Doxil Caelyx Ambisome Immunoliposomes antibodies or peptides attached on the surface for specific targeting Stealth + Target April 2008

10 1967 Term Liposome st patients to be injected with liposomes st Immunoliposome (Target) st liposome-based non-viral vector gene therapy clinical trial on cystic fibrosis patients 1995 Approved for human use anticancer drugs encapsulated in liposomes (Doxil) st liposomebased DNA vaccine 1st description of closed lipid bilayer vesicles st used as delivery systems of drug st Stealth system 1st synthetic cationic liposome deliver genes to cells st Long-circulating g Immunoliposomes (Stealth + Targeted) st used as delivery system of nucleic acids to cells st liposome-based vaccins (against hepatitis A) is marketed April 2008

11 LIPOSOMES IN GENE THERAPY April 2008

12 Lipofection = Liposome + DNA = Lipoplex

13 Clinical trials using lipofection (Total = 102) Country Disease Cancer Monogenic Vascular USA Cancer ( I / II / III ) ( I ) ( I / II ) 84 Monogenic UK 2 5 Vascular ( I ) ( I / II ) Germany 4 ( I / II ) Canada 3 ( I / II ) Switzerland 2 1 Cancer Diseases Monogenic Diseases ( I / II ) ( I ) Singapore 2 Head and neck Alpha-1-antitrypsin ( I / II ) Pancreatic Cystic fibrosisi Japan 2 Lung Canavan Disease ( I ) Breast South Corea 1 Ovarian Vascular Diseases ( I ) Renal Cardiovascular Russia 1 Prostate Coronary artery disease ( I / II ) Lymphoma Leukemia New Zeland 1 Melanoma ( I )

14 SOME COMPANIES DEVELOPING LIPOPLEXES FOR GENE/CELL THERAPY OR DNA VACCINES US Canada China UK

15 Comparison of delivery efficiency vs toxicity for various DNA transfection methods. Nature Biotechnology 18, (2000)

16 Physical-Chemistry Characterisation Structure Increase transfection of these vectors in vitro and in vivo Mode of formation Transfection mechanism

17 Most common parameters considered in the study/characterisation of lipoplexes Charge ratio (+/-) Charge ratio (+/-) = mol (cationic lipid ) mol (DNA) O Cationic lipid DOTAP N + - Cl H O O O Lipidic composition Helper lipid (neutral) O O DNA size DOPE H 3 N + O O O P O O O Saline concentration -

18 Techniques used on lipoplex characterisation Physical-Chemistry Structural Calorimetry Fluorescence Spectroscopy Infra-red Spectroscopy Dynamic light scattering Electrophoretic mobility Agarose gel electrophoresis Microscopy X-ray diffraction NMR ESR Circular Dichroism Fluorescence Resonance Energy Transfer (FRET)

19 Mode of formation -DNA Interaction (electrostatic) with lipidic monolayers Stopped-flow Calorimetry AFM miliseconds seconds - Lipidic vesicules disruption - Formation of intermediary structures with cylindric shape minutes -The unstable intermediary evolves to a multilamellar structure - Lipoplex

20 Physical-Chemistry and Structural properties of lipoplexes Physical-Chemistry properties Microscopic structure Free DNA (+) (-) Superficial charge Koltover (1997), Science, 281, Size DNA excess Lipid (+) / DNA (-) Electroneutrality Lipid Excess X-ray diffraction Electronic microscopy

21 Lamellar liquid crystal phase LαC Inverted hexagonal phase H II C (With DOPE) DNA complexes of the new dendritic lipids efficiently transfect mammalian cells in culture without cytotoxicity and, in contrast to lamellar complexes, maintain high transfection efficiency over a broad range ofcomposition. Bioconjugate Chem., 17 (4), , 2006 Hexagonal phase H C I (With Dendritic lipids) id

22 Lipofection Mechanism Vaughan, E.E.; Current Gene Therapy, 2006, 6, 671

23 Lipofection mechanism

24 Barriers to gene delivery mediated by cationic liposomes, and some strategies developed to overcome those barriers, in vitro (a) and in vivo (b). Intracellular barriers Endosomal escape of DNA (a), (b) Cytoplasmatic stability of DNA and translocation of DNA to the nucleus (a), (b) Strategies to increase transfection Endosome desrupting peptides ph-sensitive liposomes Plasmids with Nuclear Localization Signals (NLS) DNA pre-condensed with peptides Extracellular barriers DNA condensation (a), (b) Agreggation gg in serum or plasma (a), (b) Accumulation in the lungs or blood clearence (b) Targeting g of specific cells (b) Strategies to increase transfection Liposomal formulation Presence of helper lipid Mode of lipoplex preparation Transferrin or human serum albumin in liposomal formulations Use of polymers at liposome surface Use of polymers at liposome surface Use of specific ligands to target cells (specific proteins or peptides)

25 Intracellular barriers Endosomal escape of DNA (a), (b) Cytoplasmatic stability of DNA and translocation of DNA to the nucleus (a), (b) Strategies to increase transfection Endosome desrupting peptides p ph-sensitive liposomes Plasmids with Nuclear Localization Signals (NLS) DNA pre-condensed with peptides Simões et al.; Gene Therapy (1999), 6; Schwartz et al.; Gene Therapy (1999), 6; 282.

26 Extracellular barriers DNA condensation (a), (b) Agreggation in serum or plasma (a), (b) Accumulation in the lungs or blood clearence (b) Targeting of specific cells (b) Strategies to increase transfection Liposomal formulation Presence of helper lipid Mode of lipoplex preparation Transferrin or human serum albumin in liposomal formulations Use of polymers at liposome surface Use of polymers at liposome surface Use of specific ligands to target cells (specific proteins or peptides) (PIL- pegylated immunoliposomes) Chem. Soc. Rev., 2005, 34,

27 Chem. Soc. Rev., 2005, 34,

28 BUT. Manipulation of liposome surface Lipoplexes become similar to VIRUS Advantages -Specificity increase -Transfection efficiency increase Disadvantages -Large scale production more difficult and expensive -Immunogenicity increase One must find the best solution

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30 Most common parameters considered in the study/characterisation of lipoplexes and its effect in transfection Sligthly positive is better -Charge ratio -Lipidic composit. -DNA size -Saline conc. Depends on the cell line to transfect The shorter the better Prepared in low ionic strength solution There are several commercially available liposomal formulations to transfect DNA into mammalian cells frequently used in in vitro studies.

31 Transfection Chol > Diacyl Chains C14>C16>C18 Multivalent headgroups (DOSPA, DOGS) are more efficient in condensing DNA and more active than monovalent lipids (DOTAP). However strong interaction with DNA may hamper their dissociation. Stable ether linkages (DOTMA, DMRIE) are more toxic than labile ester linkages (DOTAP). Pedroso de Lima, et al; Current Medicinal Chemistry, 2003, Vol. 10, No. 14

32 Chemical structures of lipids commonly used in the formation of cationic liposomes. Several formulations may use targeting moieties such as: Transferrin, antibodies, folate, galactose, in order to increase uptake and selectivity of liposomes Lee et al.; Biochem. J. (2005), 387;1.

33 Cell type Efficiency y( (%) Viability y( (%) CHO-K HeLa HepG COS MCF PC PC NIH/3T

34 Using liposomes to transfect Stem Cells ex vivo for cellular therapy Hematopoietic Stem Cells Mesenchymal Stem Cells Neural Stem Cells

35 non adherent extremely difficult to transfect Hematopoietic stem cell HSC adhere to stroma easier to transfect

36 In vitro manipulation of Hematopoietic stem cells using liposomes Cell separation (sorting) Transfection - Immunoliposomes - Immunomagnetoliposomes Dextran-magnetite particles PEG Anti-CD34

37 In vitro manipulation of Hematopoietic stem cells using liposomes - Immunoliposomes Transfection PEG Anti-CD34 Therapeutic applications: - Hematological malignancies - Phosphonolipids Increase HSC proliferation in vitro is one of the goals - Commercial formulations, when HSC are grown in adherence to stroma or fibroblast monolayers. Lipofectamine (DOSPA:DOPE; 3:1) DOSPER DOGS (Transfectam)

38 In vitro manipulation of Mesenchymal stem cells using liposomes High proliferative capacity Low immunogeneticity - Readly transducible with vectors - Maintain transgene expression in vitro and in vivo without affecting multipotentiality Therapeutic applications: - Myocardial - Neural - Bone / Cartilage repair - Genetic deficiency syndromes - Muscular dystrophy - Leukemia Lipid-based transfection reagentshave been tested Ex:. Lipofectamine 2000, Metafectene (Biontex) For all these applications, increase MSC proliferation in vitro is one of the goals.

39 In vitro manipulation of Mesenchymal stem cells using liposomes - Cell separation (sorting sorting) Immunomagnetoliposomes -Expansion Magnetite (Fe 3 O 42 ) For simultaneous sorting and expansion Anti-CD44 or Anti-CD105 DNA or drug Antibody Other target ligand PEG Ex: Peptides Optional molecules Compulsory molecules l

40 In vitro manipulation of Neural Stem Cells using liposomes Properties: -Easily transduced ex vivo -Sustained foreign gene expression -Ability to migrate -Easily engraftable following simple implantation procedures Therapeutical applications: -Parkinson's disease -Alzheimer's disease -Multiple sclerosis -Brain ischemia -Spinal cord injury

41 In vitro manipulation of Neural Cells using liposomes Most of the studies have been accomplished using rodent neural cells There have been few studies examining i optimisation i of lipofection in neural cell types Some lipidic formulations used to transfect NSC: DOTIM:Chol (1:1) DOTAP:PC (10:1) DC-Chol:DOPEChol:DOPE Superfect (Qiagen) Lipofectin (Invitrogen) On-going work to improve transfection efficiency, Lipofectamine (Invitrogen) which is still very low ( 4-5%) Lipofectamine plus (Invitrogen) Effectent - Qiagen

42 Research in lipoplexes Portugal Lisboa Centro de Engenharia Biológica e Química, IST Prof. Joaquim Cabral Coimbra Centro de Neurociências e Biologia celular, Universidade Coimbra Estratégias para aumento de transfecção /lipoplexos com transferrina Companies in Portugal Bluepharma Pharmaceutical Company (Coimbra) ALFAMA Biotechnology company (Tagus Park) Europe: UK France Germany Sweden Holand US Canadá