Nanomedicine  The  era  of  nanotechnology  

What  is  nanotechnology?  Nanotechnology  is  science,  engineering,  and  technology  

conducted  at  the  nanoscale,  which  is  about  1  to  100  nanometers  (10-­‐9  to  10-­‐7  meters).  

To  get  a  clearer  perspective:  

•  The  diameter  of  an  atom  ranges  from  about  0.1  to  0.5  nanometers.  

•  A  sheet  of  newspaper  is  about  100,000  nanometers  thick.  

•  If  a  marble  were  a  nanometer,  one  meter  would  be  the  size  of  the  Earth.  

The  birth  of  nanotechnology  •  Concept  and  ideas  started  on  December,  1959  with  a  talk  entitled  “There’s  Plenty  

of  Room  at  the  Bottom”  by  physicist  Richard  Feynman  at  an  American  Physical  Society  meeting  at  the  California  Institute  of  Technology  (CalTech).  

•  Feynman  described  a  process  in  which  scientists  would  be  able  to  manipulate  and  control  individual  atoms  and  molecules.    

•  Over  a  decade  later,  in  his  explorations  of  ultraprecision  machining,  Professor  Norio  Taniguchi  coined  the  term  nanotechnology.    

•  Modern  nanotechnology  began  in  1981,  with  the  development  of  the  scanning  tunneling  microscope  that  could  "see"  individual  atoms.  

•  However,  MIT  researcher  K.  Eric  Drexler  popularized  the  term  and  the  concept  through  his  publication  “Engines  of  Creation”  in  1986.  

Nanotechnology  in  medicine  •  The  ability  to  manipulate  structures  and  properties  at  the  nanoscale  in  medicine  is  

like  having  a  sub-­‐microscopic  lab  bench  on  which  you  can  handle  cell  components,  viruses  or  pieces  of  DNA,  using  a  range  of  tiny  tools,  robots  and  tubes.  

•  Chemists  at  New  York  University  (NYU)  have  created  a  nanoscale  robot  from  DNA  fragments  that  walks  on  two  legs  just  10  nm  long.  

•  The  genesis  of  nanotechnology  can  be  traced  to  the  promise    of  revolutionary  advances  across  medicine,  communications,    genomics  and  robotics.  

Creating  nanobots  •  The  best  way  to  create  a  nanobot  is  to  use  another  nanobot,  the  problem  lies  in  

getting  started.    •  In  1989  a  group  of  IBM  engineers  lined  individual  atoms  up  one  by  one  until  they  

had  spelled  out  their  company’s  name.  •  The  main  difficulty  arises  with  the  fuel  unit,  since  most  conventional  forms  of  

robotic  propulsion  can’t  be  shrunk  to  nanoscale  with  current  technology.  Scientists  have  succeeded  in  reducing  a  robot  to  five  or  six  millimeters,  but  this  size  still  technically  qualifies  it  as  a  macro-­‐robot.  

•  Aerodynamic,  durable,  smooth-­‐moving.    

Nanosponges  •  A  team  of  researchers  at  the  University  of  California,  San  Diego  led  by  Professor  

Liangfang  Zhang,  have  developed  biomimetic  nanosponges  that  could  deal  with  antibiotic-­‐resistant  infections.    

•  Each  nanosponge  is  a  tiny  polymer-­‐based  particle  measuring  85nm  across  that's  been  wrapped  in  a  red  blood  cell  membrane.    

•  A  clinical  trial  on  mice  tested  their  efficacy  against  a  lethal  dose  of  a  bacterial  toxin  from  Methicillin-­‐resistant  Staphylococcus  aureus  (MRSA).  The  toxic  proteins  attached  themselves  to  the    nanosponges  and  were  harmlessly  transported  to  the  liver  for    removal.  

Nanosponges:  Trials  •  When  dosed  with  the  nanosponges  before  being  injected  with  the  toxin,  89  

percent  of  the  mice  survived.  When  treated  after  being  infected,  44  percent  of  the  mice  lived.  When  dosed  at  exactly  the  same  time,  the  mice  suffered  no  adverse  effects,  even  with  a  70-­‐to-­‐one  ratio  of  toxin  and  nanosponges.    

•  The  polymer  used  for  the  nanosponges  has  already  been  approved  by  the  FDA,  and  the  red  blood  cell  membrane  is  taken  from  the  body,  meaning  there  are  no  new  chemical  compounds  to  approve.  

Advantages  of  nanomedicine  •  Site-­‐specific,  targeted  drug  delivery  using  nanoparticles  is  more  effective:  improved  bioavailability,  minimal  

side  effects,  decreased  toxicity  to  other  organs,  and  less  cost;  feasible  in  hydrophobic  and  hydrophilic  states  through  variable  routes  of  administration,  including  oral,  vascular,  and  inhalation.  (Example  -­‐  cancer)  

•  With  gene  therapy,  a  normal  gene  can  be  inserted  in  place  of  an  abnormal,  disease-­‐causing  gene  using  nanoparticles  as  carrier  molecules.  

•  Open  doors  to  new  possibilities  under  research    

With  nanomachines,  we  could:    

•  Better  design  and  synthesize  pharmaceuticals.  

•  Directly  treat  diseased  cells  like  cancer.  

•  Better  monitor  the  life  signs  of  a  patient.  

•  Use  nanomachines  to  make  microscopic  repairs  in  hard-­‐to-­‐operate-­‐on  areas  of  the  body.  

•  Potentially  eliminate  other  ethical  issues  (e.g.  assembling  beef  instead  of  slaughtering  cows,  constructing  cells  rather  than  getting  them  from  reproduction,  etc...).  

•  Cleaning  up  toxins  or  oil  spills.  

Disadvantages  •  Problems  could  arise  from  the  inhalation  of  microscopic  particles,  similar  to  

inhaling  minute  asbestos  particles.  

•  The  possible  toxic  health  effects  of  these  NPs  associated  with  human  exposure  are  unknown.  This  means  we  have  an  ethical  duty  to  take  precautionary  measures  regarding  their  use.    

•  Exposure  to  ultrafine  particles  (UFPs)  can  have  especially  harsh  cardiopulmonary  outcomes.  The  comparability  of  engineered  nanoparticles  to  UFPs  suggests  that  the  human  health  effects  are  likely  to  be  similar.  Therefore,  it  is  prudent  to  elucidate  their  toxicologic  effect  to  minimize  occupational  and  environmental  exposure.  

•  Nanotoxicology.  

Something to think about. “A new technology will only be successful if those promoting it can show that it is safe, but history is littered with examples of promising technologies that never fulfilled their true potential and/or caused untold damage because early warnings about safety problems were ignored. The nanotechnology community stands to benefit by learning lessons from this history.” - Steffen Foss Hansen

Miniature  robots  that  we  can’t  see,  what  could  possibly  go  wrong?    

•  Biological  reactions  towards  nanotechnology.  

•  Potential  attack  of  biological  organisms  at  molecular  levels.  

•  Miniature  weapons  and  explosives.  

•  Disassemblers  to  attack  physical  structures.  

•  Surveillance  •  Monitoring  

•  Tracking  

The  Grey  Goo  Scenario  •  A  hazard  Drexler  already  foresaw  in  Engines  of  

Creation,  in  which  he  outlined  the  possibilities  and  consequences  of  this  emerging  field,  would  be  if  general  purpose  disassemblers  got  loose  in  the  environment  and  started  disassembling  every  molecule  they  encountered.  This  is  known  as  "The  Gray  Goo  Scenario."    

•  Furthermore,  if  nanomachines  were  created  to  be  self  replicating  and  there  were  a  problem  with  their  limiting  mechanism,  they  would  multiply  endlessly  like  viruses.  

Issues  •  How  can  we  establish  agreements  or  conventions  around  so  many  

different  fields  of  development?  

•  Building  principles  around  the  matter.  

•  Should  there  be  policies  regarding  development?    

•  Do  we  need  international  laws  that  trace  limits  for  a  safe  development?  

•  Are  we  interfering  too  much  with  nature?    (Religious/ethical  debate.)  

What’s  next?  Molecular  nanotechnology.    

•  Speculative  subfield  of  nanotechnology:  engineering  molecular  assemblers,  machines  which  could  re-­‐order  matter  at  a  molecular  or  atomic  scale.    

•  Still  highly  theoretical:  the  proposed  elements  of  molecular  nanotechnology,  such  as  molecular  assemblers  and  nanorobots  are  far  beyond  current  capabilities.  

Is this the future of medicine? Will we revolutionize the way we cure diseases?

Bibliography  Chen,  A.  (n.d.).  The  Ethics  of  Nanotechnology.  Retrieved  March  11,  2014,  from  Santa  Clara  University:  http://www.scu.edu/ethics/

publications/submitted/chen/nanotechnology.html  

National  Nanotechnology  Initiative.  (n.d.).  What  is  Nanotechnology?  Retrieved  March  11,  2014,  from  United  States  National  Nanotechnology  Initiative:  http://www.nano.gov/nanotech-­‐101/what/definition  

Radford,  T.  (2003,  April  29).  Brave  new  world  or  miniature  menace?  Why  Charles  fears  grey  goo  nightmare.  Retrieved  March  11,  2014,  from  The  Guardian:  http://www.theguardian.com/science/2003/apr/29/nanotechnology.science  

Souppouris,  A.  (2013,  April  15).  Nanosponges  could  soak  up  deadly  infections  like  MRSA  from  your  bloodstream.  Retrieved  March  11,  2014,  from  The  Verge:  http://www.theverge.com/2013/4/15/4225834/nanosponges-­‐kill-­‐deadly-­‐bacteria-­‐mrsa-­‐clinical-­‐trial  

 Vallyathan,  M.  R.  (2006,  December).  Nanoparticles:  Health  Effects—Pros  and  Cons.  Retrieved  from  The  National  Center  for  Biotechnology  Information  :  http://www.ncbi.nlm.nih.gov/pmc/articles/PMC1764161/  

   Caruthers,  SD.  (2007,  March  16)  Wickline  SA,  Lanza  GM.  Nanotechnological  applications  in  medicine.  Curr  Opin  Biotechnol.