• Two of most promising technologies of future:
– Biotechnology: Use of living in the creation of wealth (products or processes)
– Nanotechnology: creation, investigation and utilisation of systems that are 1000 times smaller than the components currently used in the field of microelectronics.
• The interface of these two worlds lies Nanobiotechnology
– It uses nanotechnology to analyse and create biological nanosystems
– It uses biological materials and structural plans to produce technical, functional nanosystems

• Functional biological assemblies are inspiration for nanotechnological systems and devices
• Molecular recognition btw. building blocks self-assembly formation of functional devices
• motors, pumps, cables, etc, all functioning at the nano-scale

• Interaction between biological and non-biological devices???
– Interactions with biological as well as non-biological substrates
– Toxicity
– How does nature make use of adhesive and anti-adhesive interactions?
• Screening methods in biology
– Bio-Chips
– Lab-on-a-chip
• Nanotechnologically modified biomaterials
– Nano aspects of biological systems
– Nanotechnological tools to improve biomaterials
• Nanoparticles as therapeutic drug carriers and diagnostics
– Drug, oligonucleotide, imaging agents
• Nanodevices in medicine, pharmacy and biology

Gazid E., FEBS Journal, 2006
DNA is very suitable for nanotechnological applications from the material science point of view:
1.
The diameter of ssDNA is less than 1 nm
2.
DNA molecules are chemically very robust
3.
Low cost of large-scale chemical DNA synthesis
4.
Easy modification: for example, by biotinylation or thiolation

Gazid E., FEBS Journal, 2006
Examples:
• DNA used in the formation of nanowires (1998): Metallization of dsDNA btw two gold electrodes to form conductive silver nanowire
• DNA-binding proteins (Figure)

a) Holliday junction b) Assembly of gold nanoparticles c) Immobilization of gold NP d) PCR mediated introduction of new fuctionalities to create DNAprotein hybrids e) Self-replication of connectivity

Yusko, E.C et. al, Nature Nanotechnology, 6:253 –260, 2011
Challenges to reach the full potential of nanopore-based sensing:
• reliable fabrication of synthetic nanopores on the sub-nanometre scale
• better control of translocation times of single-molecule analytes
• methods to control the surface chemistry inside synthetic pores: reduce non-specific interactions of analytes with the pore walls and prevent pore clogging
• low frequency of translocation events at low analyte concentrations and the poor specificity of the nanopores for analytes need to be improved

Yusko, E.C et. al, Nature Nanotechnology, 6:253 –260, 2011
Fig 1: Insects detect pheromones by translocating odorant molecules through lipid-coated nanopores (D:
6 –65 nm)
Fig 2: Lipid coatings are thought to participate in the capture, preconcentration and subsequent translocation of odorants to specific receptors
Fig 3: Capture, affinity-dependent pre-concentration and translocation of specific proteins after binding to ligands on mobile lipid anchors

Yusko, E.C et. al, Nature Nanotechnology, 6:253 –260, 2011
• Clogging Problem: Amyloidogenic peptides: e.g.
Alzheimer's disease-related amyloid-beta (A β) peptides

Self-Assembly of a Viral Molecular
Machine from Purified Protein and RNA
Constituents
Poranen et al, Molecular Cell, Vol. 7, 845 –854,
2001
• Understanding of self-assembly in nature…

Cellular imaging

Photo-thermal therapy

MRI and Cell Tracking
 Fate of cells in the implanted area
Anticancer therapy

• Controlled drug-delivery systems deliver drugs in the optimum dosage for long periods
– increasing the efficacy of the drug
– maximizing patient comfort
– enhancing the ability to use highly toxic, poorly soluble or relatively unstable drugs
• Nanoscale materials can be used as drug delivery vehicles to develop highly selective and effective therapeutic and diagnostic systems
• Nano vs micro
– nanoscale particles can travel through the blood stream without sedimentation or blockage of the microvasculature
– Small nanoparticles can circulate in the body and penetrate tissues
– nanoparticles can be taken up by the cells through natural means such as endocytosis

• Particle Size, Surface-to-Volume Ratio, Surface Area, and Surface Free
Energy
• Biological Reactivity
•
Opsonisation: thought to be the greatest threat engulfment of foreign particles injected into the blood stream by specific macrophages cells of
RES (reticulo endothelial system)
Modifications:
• Nonadhesive surface coatings
• Attachment of molecules for targetting
• Layer-by-layer methods: shown to regulate nanoparticle biodistribution: cationic pegylated liposomes are preferantially uptaken by the liver and tumor vessels in stead of spleen and blood accumulation
• Synthesis from amphiphilic polymers

Nano-Layered Microneedles for Transcutaneous Delivery of Polymer
Nanoparticles and Plasmid DNA
DeMuth et al, 2010, Advanced Materials
Luciferase gene and lipid-coated
PLGA NPs were delivered seperately.
A) SEM micrograph of uncoated
PLGA microneedle arrays
B) Polyelectrolyte layers
A) 24 bilayers for 5 min
B) 1 bilayer for 24 h
C) 5 bilayers for 24 h
D) 24 bilayers for 24 h

Nanoparticles for ex vivo siRNA delivery to dendritic cells for cancer vaccines: Programmed endosomal escape and dissociation
Akita et al (2010) and Kogure et al (2007) J. Cont. Rel
Solution??
• Programmed packaging

Targeted PLGA nano- but not microparticles specifically deliver antigen to human dendritic cells via DC-SIGN in vitro
Cruz et al (2010), J. Cont. Rel.
• Specific targeting of NPs to human
DCs enhances antigen presentation

• It can complement existing technologies for detection, prevention, diagnosis and treatment
• Useful in the area of biomarker research and increase sensitivity in assays with relatively small sample volume
Jain, KK, BMC Medicine 2010, 8:83

– Fabrication: top-down, bottom-up
– Modification: Microfabrication and nanofabrication to modify surface properties with resolutions as small as
50 nm control of cell behavior, orienting cells and guiding cell migration, differentiation??

Cell interactions with hierarchically structured nanopatterned adhesive surfaces
Arnold, M, et al, Soft Matter, 2009, 5, 72
• Counting the number of clustering cell adhesion based transmembrane proteins is performed by molecular defined, biofunctionalised nanopatterns of defined single protein binding sites confined in micrometre large areas, i.e. hierarchically organised micro-nanopattern

Review: Calderon et al, Amino Acids (2011) 40:29 –49
• Cationic nanoparticles formed by the conjugation of cholesterol and antimicrobial peptides (AMPs): to cross the blood –brain barrier for treatment of fatal
Cryptococcal (Wang et al. Biomaterials 31(10):2874 –
2881 2010)
• Nanostructured thin films with immobilized AMPs as an agent intended to combat and prevent infection and formation of Staphylococcus biofilm related implant failure (Shukla et al. Biomaterials 31(8):2348 –2357,
2009)

1. Park, S; Hamad-Schifferli, K, Current Opinion in Chemical Biology, 14: 616-
622, 2010
2. You, et al, Nano Today 2 (2007), 34 –43
3. Park and K. Hamad-Schifferli, ACS Nano 4 (2010), 2555
–2560
• The biological behavior of nanomaterials depends primarily on how they interface to biomolecules and their surroundings
• Issues like non-specific adsorption (NSA) are still the biggest obstacles and have held back widespread practical use of nanotechnology in biology

Utilizing NSA:
(a) Tunable intracellular release from
NP –DNA ‘nanoplexes’
(b) Enhancing protein translation: In vitro gene expression with DNA,
AuNP recruits mRNA and translation related molecules into its proximity
(c) Protein coronas induce a biological response

Communication???
• Nanomechanical
• Acoustical
• Electromagnetic
• Chemical or Molecular
Short-range:
• Molecular motors
• Ca 2+ signalling
Long-range:
• Pheromones