Supercritical_NP1 CO2_FO Emerging_JJ as_CSA Transplant_NN1 Tissue_NN1 Sterilization_NN1 Option_NN1 When_CS replacing_VVG a_AT1 torn_JJ anterior_JJ cruciate_NN1 ligament_NN1 (_( ACL_NP1 )_) or_CC using_VVG bone_NN1 tissue_NN1 in_II spinal_JJ fusion_NN1 to_TO treat_VVI vertebral_JJ problems_NN2 ,_, the_AT last_MD thing_NN1 that_CST a_AT1 doctor_NN1 or_CC patient_NN1 wants_VVZ to_TO worry_VVI about_RP is_VBZ an_AT1 infection_NN1 or_CC the_AT structural_JJ integrity_NN1 of_IO the_AT replacement_NN1 part_NN1 ._. 
For_IF this_DD1 reason_NN1 tissues_NN2 are_VBR screened_VVN ,_, cleaned_VVN and_CC processed_VVN to_TO meet_VVI U.S._NP1 Food_NN1 and_CC Drug_NN1 Administration_NN1 (_( FDA_NP1 )_) guidelines_NN2 ._. 
During_II processing_NN1 ,_, however_RR ,_, some_DD tissues_NN2 are_VBR sterilized_VVN typically_RR by_II irradiating_VVG the_AT replacement_NN1 part_NN1 or_CC tissue_NN1 ,_, and_CC this_DD1 process_NN1 can_VM undermine_VVI its_APPGE strength_NN1 ._. 
So_RR ,_, a_AT1 new_JJ approach_NN1 is_VBZ emerging_VVG as_II an_AT1 alternative_JJ --_JJ "_" supercritical_JJ "_" carbon_NN1 dioxide_NN1 ,_, compressed_VVN to_II somewhere_RL between_II a_AT1 gaseous_JJ and_CC liquid_JJ state_NN1 ._. 
When_CS carbon_NN1 dioxide_NN1 is_VBZ compressed_VVN to_II nearly_RR 10_MC times_NNT2 atmospheric_JJ pressure_NN1 ,_, or_CC around_RG 10_MC kilograms_NNU2 per_II centimeter_NN1 ,_, and_CC heated_VVN to_II 35_MC degrees_NN2 Celsius_NP1 ,_, it_PPH1 forms_VVZ what_DDQ is_VBZ known_VVN as_II a_AT1 supercritical_JJ fluid_NN1 --_NN1 a_AT1 wet_JJ gas_NN1 that_CST can_VM permeate_VVI surfaces_NN2 and_CC has_VHZ some_DD of_IO the_AT dissolving_JJ properties_NN2 of_IO liquids_NN2 ,_, as_RR21 well_RR22 ._. 
After_CS transplant_NN1 tissue_NN1 has_VHZ been_VBN cleaned_VVN and_CC sealed_VVN in_II its_APPGE final_JJ medical_JJ packaging_NN1 ,_, these_DD2 bone_NN1 fragments_NN2 ,_, tendons_NN2 or_CC even_RR skin_VV0 grafts_NN2 are_VBR placed_VVN in_II baskets_NN2 within_II a_AT1 high-pressure_JJ chamber_NN1 ._. 
Once_RR sealed_VVN ,_, an_AT1 automated_JJ system_NN1 fills_VVZ the_AT chamber_NN1 with_IW CO2_FO and_CC then_RT pressurizes_VVZ and_CC heats_NN2 it_PPH1 above_II the_AT critical_JJ point_NN1 where_RRQ the_AT gas_NN1 forms_VVZ a_AT1 solvent_NN1 that_CST sterilizes_VVZ the_AT samples_NN2 within_II a_AT1 few_DA2 hours_NNT2 ._. 
Supercritical_NP1 CO2_FO can_VM prompt_VVI the_AT formation_NN1 of_IO the_AT related_JJ carbonic_JJ acid_NN1 ,_, which_DDQ ,_, along_II21 with_II22 chemical_JJ oxidation_NN1 ,_, may_VM kill_VVI the_AT bacteria_NN2 ._. 
Evidence_NN1 for_IF using_VVG supercritical_JJ CO2_FO for_IF sterilization_NN1 dates_VVZ back_RP a_AT1 decade_NNT1 when_RRQ a_AT1 team_NN1 of_IO Massachusetts_NP1 Institute_NN1 of_IO Technology_NN1 researchers_NN2 reported_VVN in_II Proceedings_NN2 of_IO the_AT National_JJ Academy_NN1 of_IO Sciences_NN2 the_AT use_NN1 of_IO this_DD1 form_NN1 of_IO carbon_NN1 dioxide_NN1 to_TO deactivate_VVI live_JJ bacteria_NN2 ._. 
Within_II a_AT1 year_NNT1 ,_, NovaSterilis_NP1 in_II Lansing_NP1 ,_, N.Y._NP1 ,_, formed_VVD to_TO commercialize_VVI the_AT process_NN1 with_IW larger_JJR automated_JJ systems_NN2 that_CST could_VM use_VVI supercritical_JJ CO2_FO to_TO sterilize_VVI tissue_NN1 ._. 
Today_RT ,_, the_AT company_NN1 's_GE Nova_FW 2200_MC features_VVZ a_AT1 20-liter_JJ sterilization_NN1 chamber_NN1 in_II which_DDQ up_RG21 to_RG22 60_MC individual_JJ allografts_NN2 (_( transplant_NN1 tissues_NN2 )_) can_VM be_VBI purified_VVN ._. 
To_TO deactivate_VVI spores_NN2 as_II31 well_II32 as_II33 live_JJ bacteria_NN2 ,_, the_AT company_NN1 provides_VVZ sheets_NN2 of_IO paper_NN1 treated_VVN with_IW a_AT1 mix_NN1 of_IO chemical_JJ additives_NN2 including_II an_AT1 acid_NN1 that_CST can_VM be_VBI dissolved_VVN into_II the_AT supercritical_JJ CO2_FO sterilizing_VVG fluid_NN1 ,_, much_RR like_II detergent_NN1 in_II a_AT1 washing_NN1 machine_NN1 ,_, NovaSterilis_NP1 President_NN1 and_CC Chief_JJ Executive_NN1 David_NP1 Burns_NP1 says_VVZ ._. 
The_AT fluid_NN1 penetrates_VVZ bacterial_JJ cells_NN2 and_CC kills_VVZ them_PPHO2 ._. 
The_AT demand_NN1 for_IF replacement_NN1 bone_NN1 and_CC tendons_NN2 is_VBZ great_JJ --_NN1 about_RG 1.7_MC million_NNO musculoskeletal_JJ allograft_NN1 tissues_NN2 are_VBR processed_VVN in_II the_AT U.S._NP1 annually_RR ,_, according_II21 to_II22 the_AT American_JJ Association_NN1 of_IO Tissue_NN1 Banks_NN2 '_GE (_( AATB_NP1 )_) Annual_JJ Survey_NN1 Report_NN1 2007_MC ._. 
The_AT supercritical_JJ approach_NN1 is_VBZ getting_VVG a_AT1 toehold_NN1 in_II this_DD1 industry_NN1 ._. 
Burns_NP1 says_VVZ that_CST five_MC tissue-processing_JJ companies_NN2 have_VH0 licensed_VVN the_AT NovaSterilis_NN1 technology_NN1 ._. 
Bone_NN1 ,_, tendon_NN1 and_CC skin_NN1 samples_NN2 treated_VVN with_IW the_AT high-pressure_NN1 CO2_FO have_VH0 not_XX shown_VVN any_DD reduced_JJ structural_JJ integrity_NN1 ,_, according_II21 to_II22 at_RR21 least_RR22 two_MC studies_NN2 conducted_VVN by_II biomedical_JJ company_NN1 researchers_NN2 and_CC published_VVN in_II peer-reviewed_JJ journals_NN2 ,_, offering_VVG an_AT1 alternative_NN1 to_II irradiation_NN1 and_CC providing_VVG replacement_NN1 parts_NN2 that_CST reach_VV0 FDA_NN1 sterilization_NN1 standards_NN2 on_II par_NN1 with_IW those_DD2 for_IF medical_JJ devices_NN2 ._. 
Bathing_VVG allografts_NN2 in_II supercritical_JJ CO2_FO has_VHZ other_JJ practical_JJ advantages_NN2 ,_, as_RR21 well_RR22 ._. 
Supercritical_JJ treatment_NN1 allows_VVZ tissue_NN1 banks_NN2 to_TO process_VVI their_APPGE own_DA products_NN2 on_II site_NN1 and_CC within_II a_AT1 few_DA2 hours_NNT2 rather_II21 than_II22 shipping_NN1 samples_VVZ out_RP for_IF decontamination_NN1 ._. 
Because_II21 of_II22 the_AT expense_NN1 and_CC governmental_JJ regulations_NN2 associated_VVN with_IW using_VVG radiation_NN1 ,_, tissue_NN1 banks_NN2 do_VD0 n't_XX irradiate_VVI their_APPGE own_DA tissues_NN2 ._. 
Instead_RR ,_, they_PPHS2 ship_VV0 samples_NN2 to_II facilities_NN2 with_IW the_AT necessary_JJ licenses_NN2 and_CC expertise_NN1 ._. 
That_DD1 process_NN1 is_VBZ ,_, however_RR ,_, both_RR time_NNT1 consuming_VVG and_CC expensive_JJ ,_, says_VVZ Sharon_NP1 Bryce_NP1 ,_, director_NN1 of_IO tissue_NN1 services_NN2 for_IF Australian_JJ Biotechnologies_NN2 ,_, a_AT1 New_NP1 South_NP1 Wales_NP1 biotech_NN1 firm_NN1 that_CST expects_VVZ to_TO get_VVI approval_NN1 from_II the_AT Therapeutic_JJ Goods_NN2 Administration_NN1 (_( TGA_NP1 )_) ,_, Australia_NP1 's_GE regulatory_JJ equivalent_NN1 of_IO the_AT FDA_NN1 ,_, to_TO use_VVI supercritical_JJ carbon_NN1 dioxide_NN1 to_TO sterilize_VVI one_MC1 of_IO their_APPGE bone_NN1 products_NN2 by_II the_AT end_NN1 of_IO this_DD1 year_NNT1 ._. 
And_CC like_JJ irradiation_NN1 ,_, the_AT CO2_FO process_NN1 can_VM be_VBI performed_VVN while_CS the_AT samples_NN2 are_VBR sealed_VVN within_II their_APPGE final_JJ packaging_NN1 ,_, reducing_VVG the_AT opportunity_NN1 for_IF contaminants_NN2 to_TO be_VBI reintroduced_VVN ._. 
The_AT problem_NN1 with_IW high_JJ doses_NN2 of_IO gamma_NN1 radiation_NN1 ,_, or_CC harsh_JJ treatments_NN2 including_II steam_NN1 and_CC chemicals_NN2 such_II21 as_II22 ethylene_NN1 oxide_NN1 (_( a_AT1 fumigant_NN1 known_VVN to_TO cause_VVI respiratory_JJ irritation_NN1 and_CC lung_NN1 injury_NN1 )_) ,_, is_VBZ that_DD1 they_PPHS2 can_VM degrade_VVI collagen_NN1 and_CC other_JJ proteins_NN2 within_II bone_NN1 and_CC soft_JJ tissue_NN1 ,_, compromising_VVG their_APPGE strength_NN1 and_CC rendering_VVG them_PPHO2 unusable_JJ for_IF grafts_NN2 ,_, notes_NN2 AATB_VV0 Chief_JJ Policy_NN1 Officer_NN1 Scott_NP1 Brubaker_NP1 ._. 
Bryce_NN1 adds_VVZ :_: "_" Gamma_NN1 irradiation_NN1 is_VBZ actually_RR quite_RG harsh_JJ to_II the_AT bone_NN1 ._. 
We_PPIS2 walk_VV0 a_AT1 fine_JJ tightrope_NN1 in_II our_APPGE company_NN1 ,_, "_" using_VVG low-dose_JJ radiation_NN1 to_TO sterilize_VVI while_CS trying_VVG to_TO avoid_VVI structural_JJ degradation_NN1 ._. 
Some_DD surgeons_NN2 have_VH0 been_VBN impressed_VVN with_IW the_AT supercritical_JJ process_NN1 so_RG far_RR ,_, says_VVZ Bruce_NP1 Humphrey_NP1 ,_, president_NN1 of_IO Integrity_NN1 Bio-Surgical_JJ Systems_NN2 in_II Andover_NP1 ,_, N.J._NP1 ,_, which_DDQ distributes_VVZ soft_JJ tissues_NN2 ,_, including_II some_DD sterilized_VVD with_IW supercritical_JJ CO2_FO ._. 
Although_CS tissue_NN1 banks_NN2 still_RR have_VH0 to_TO be_VBI convinced_VVN of_IO the_AT value_NN1 of_IO investing_VVG in_II the_AT new_JJ technology_NN1 ,_, Humphrey_NP1 is_VBZ optimistic_JJ about_II its_APPGE future_NN1 ._. 
"_" I_PPIS1 see_VV0 the_AT process_NN1 becoming_VVG a_AT1 standard_NN1 in_II the_AT industry_NN1 ,_, "_" he_PPHS1 says_VVZ ._. 
