NANYANG RESEARCH PROGRAMME -SPMS07 DNA Origami Assembled by DNA - PowerPoint PPT Presentation

NANYANG RESEARCH PROGRAMME -SPMS07 DNA Origami Assembled by DNA Dendrimers for Drug Delivery Liu Haoyun Temasek Junior College

OVERVIEW 1. INTRODUCTION 2.AIM 3.METHEDOLOGY 4.DISCUSSION OF RESULTS 5.CONCLUSION

1. INTRODUCTION 1.1 DNA DENDRIMERS  Definition: - Molecules formed by the attachment of DNA molecules to a typically symmetrical core -Basic building blocks of the DNA scaffold in DNA hydrogels

1. INTRODUCTION 1.2 DNA HYDROGELS  Definition - Polymeric networks formed by DNA dendrimers

1. INTRODUCTION 1.2 DNA HYDROGELS  Characteristics: - Bio-compatibility - Molecular recognition capacity - Nano-scale control capability

1. INTRODUCTION 1.2 DNA HYDROGELS  Applications: - Bio-sensing - 3D growing medium - Specific drug delivery

2. AIM  To synthesize DNA dendrimers and assemble DNA nano-hydrogels that could potentially be used in specific drug delivery

3. METHODOLOGY  3.1 SYNTHESIS OF DENDRITIC DNA  3.2 PURIFICATION OF DENDRITIC DNA  3.3 SELF-ASSEMBLY OF DNA NANOHYDROGEL

3. METHODOLOGY 3.1 SYNTHESIS OF DENDRITIC DNA  Synthesis of DNA using long trebler phosphoamidite as the branching reagent through Bioautomation Mermaid 4 via solid phase oligonucleotide synthesis  Synthesized dendritic DNA consisted of 1 loading branch for functionalizing and 3 gelation branches for hybridization

3. METHODOLOGY 3.1 SYNTHESIS OF DENDRITIC DNA  Cleavage of DNA molecules from the controlled pore glass via incubation in 1ml of 33% NH4OH solution at 25 ° C for 10 minutes  Deprotection of the DNA through controlled heating at 60 ° C in a dry bath

3. METHODOLOGY 3.2 PURIFICATION OF DENDRITIC DNA  Purification of the dendritic DNA was achieved through Reverse Phase HPLC with polar phase being 0.1 M TEAA pH7 and non-polar phase ACN  DNA was collected in TEAA

3. METHODOLOGY 3.2 PURIFICATION OF DENDRITIC DNA  Dendritic DNA was incubated in 200µl of 80% acetic acid for 15 minutes for the cleavage of DMT group  Second round of HPLC to separate pure dendritic DNA from the DMT group.

3. METHODOLOGY 3.3 SELF-ASSEMBLY OF DNA NANOHYDROGEL  200nM purified dendritic DNA was mixed with 200nM of linker DNA  The mixture was heated in 95 ° C dry bath for 10 minutes for DNA annealing and cooled down naturally for self-assembly  Resultant DNA nanohydrogels collected and concentrated though centrifugation

4. DISCUSSION OF RESULTS 4.1 DNA DENDRIMER SYNTHESIS  Sequence of synthesized dendritic DNA : (CGA TTA CAG CTT GCT)3 D TTTCGA TCG  Molecular weight derived from MALDI-TOF showed a reading of 16640.73

4. DISCUSSION OF RESULTS 4.1 DNA DENDRIMER SYNTHESIS  Theoretical molecular weight was 16945.16  Synthesized DNA dendrimers were usable

4. DISCUSSION OF RESULTS 4.2 DNA NANO HYDROGEL SYNTHESIS  Synthesized DNA nanohydrogels was examined under AFM to determine their size  An average size was108.853nm

4. DISCUSSION OF RESULTS 4.2 DNA NANO HYDROGEL SYNTHESIS  Data collected from AFM verified through DLS  The readings collected from DLS showed an average size of 129.1nm  possibly due to the fact that theDNA nanohydrogel was in vacuum-driedstate in AFM

5. CONCLUSION  The DNA nanohydrogels were synthesized successfully from DNA dendrimers and are ready for loading of Doxorubicin for drug test

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