Bio-Technology R&D: Bio-Technology R&D: Performance Enhancement & Innovative Product Development Through Pore Structure Akshaya Jena and Krishna Gupta Porous Materials, Inc. Ithaca, NY, USA

Dependence of Performance on Pore Structure Characteristics  Many innovative products are currently being increasingly used in biotech industries including; ◦ Health care ◦ Medical ◦ Pharmaceutical  Examples of such products; ◦ Substrates for tissue growth ◦ Drug delivery systems ◦ Implants ◦ Wound dressings ◦ Arterial grafts ◦ Filters for separation of bacteria from body fluids, ◦ Substrates for organ culture  Pore structure of these products governs the flow and the kinetics of the bio-chemical processes which occur during applications

Dependence of Performance on Pore Structure Characteristics  Performance dependent on their pore structure characteristic  Influence of application environment on pore structure needs to be determined ◦ Chemical environment ◦ Operating temperature ◦ Humidity ◦ Stresses generated during the operation Pore structure characteristics which need to be determined: Pore diameter Through pore throat diameter Pore distribution Pore volume Porosity Pore surface area Hydrophobic and hydrophilic nature of pores Gas and liquid permeability Water vapor transmission rate Diffusional flow rate

Techniques for Measurement of Pore Structure Characteristic  Many techniques are available for evaluation of pore structure characteristics relevant for bio- technical applications

Techniques for Measurement of Pore Structure Characteristic  Liquid Extrusion Porosimetry Liquid Extrusion Porosimetry ◦ Measures  Through pore volume  Through pore diameters  Pore distribution  Hydrophobic through pores  Hydrophilic through pores  Structure over a range of: o Temperature o Stress o Chemical environment o Controlled humidity

 Capillary Flow Porometry Capillary Flow Porometry ◦ Measures  Wide range of through pore throat diameters  Pore distribution  Gas permeability  Structure over a range of  Temperature  Stress  Chemical environment  Controlled humidity  Permeametry Permeametry ◦ Measures  Gas, vapor, and liquid transmission rates  Many chemical species  Over wide range of concentration, temperature, and stress on the sample Techniques for Measurement of Pore Structure Characteristic

 Water Vapor and Gas Transmission Analysis Water Vapor and Gas Transmission Analysis o Measures  Water vapor transmission rate  Uses many gradient: o Humidity o Temperature o Concentration o Pressure  Vacuapore Vacuapore o Measures  Through and blind hydrophobic pore volume  Through and blind hydrophobic pore diameter  Distribution of hydrophobic pores Techniques for Measurement of Pore Structure Characteristic

 Mercury Intrusion Porosimetry Mercury Intrusion Porosimetry ◦ Measures  Through and blind pore volume and diameter  BET Sorptometry BET Sorptometry ◦ Measures  Surface area of through and blind pores  Very small through and blind pore volume  Pore diameter and distribution  Chemisorptions of many chemicals over a wide range of temperatures and pressures  Pycnometry Pycnometry ◦ Measures  True and bulk density Techniques for Measurement of Pore Structure Characteristic

How Can PMI Help?  What is PMI? ◦ Porous Materials, Inc. designs, manufactures, and sells instruments for pore structure characterization Porous Materials, Inc. ◦ Has vast experience in patenting of novel technology for pore structure characterization and developing custom instruments for a wide variety of applications

How Can PMI Help?  What is PMI?PMI ◦ Has published many papers and presented many oral and poster papers in conferences on pore structure characterization of the products of biotech industries ◦ Has supplied instruments to many biotech related industries and research laboratories all over the globe

Pore Structure Characterization Instruments by PMI PMI Liquid Extrusion Porosimeter PMI Advanced Capillary Flow Porometer Specially designed for biotech industry o Wide range of through pores o Wide range of sample sizes including miniature samples

Pore Structure Characterization Instruments by PMI Water Vapor Water Vapor & Gas Diffusion Analyzers & PermeametersGas Diffusion Analyzers & Permeameters Unique products widely used in the biotech industry

PMI Vacuapore PMI Mercury Intrusion Porosimeter Pore Structure Characterization Instruments by PMI Suitable for analysis of hydrophobic and hydrophilic pores

Pore Structure Characterization Instruments by PMI Gas Pycnometer BET Sorptometer All instruments needed to investigate pore structure in the biotech industry are manufactured by PMI.

All PMI Instruments Fully Automated  Fully automated ◦ Test execution ◦ Data acquisition ◦ Data storage ◦ Data reduction  Windows-based, menu driven, simple operation  Objective, accurate reproducible results

PMI In-House Contract Testing Laboratory  Performs tests on biotech samples submitted from all over the globe  Test time can be as short as two days

Example of Application of PMI Instruments Pore Structure Characterization of Substrates for Tissue Growth and Culture

Through Pore Volume  Instruments used to measure through pore volume ◦ PMI Liquid Extrusion Porosimeter PMI Liquid Extrusion Porosimeter  Only through pores relevant for biotechnology measured  Large 500  m pores measureable  Highly repeatable  Click here for more information on this topic Click here

Through Pore Distribution  Instruments used to measure through pore distribution ◦ Volume distribution of the through pores: PMI Liquid Extrusion Porosimeter ◦ Volume distribution of through and blind pores: PMI Mercury Intrusion Porosimeter  Expected identical pore volume by both methods (No blind pore in nanofiber substrate)  Expected high Porosity, 81.7%  Much higher resolution by liquid extrusion technique  High pressures and toxic mercury completely avoided by extrusion technique

Characteristics of Through Pore Throat Diameters  Through pore throat diameters determine nutrient and drug permeation rate and govern separation of entities like bacteria from body fluids, drugs, drinking water, food and beverages.  Instrument used to measure through pore throat diameters : PMI Capillary Flow PorometerPMI Capillary Flow Porometer ◦ Measures  The largest pore throat diameter  Mean flow pore throat diameter  Pore distribution  Click here for more information on this topic Click here

 Narrow distribution demonstrated (The largest throat diameter is 2.91  m and the mean is 1.65  m )  The flow based mean throat diameter (1.65  m) is close to the volume based median pore diameter (3.27  m)  Results suggest inappreciable change in pore diameter along pore path  Click here for more information on this topic Click here Characteristics of Through Pore Throat Diameters Distribution of through pore throat diameters in a nanofiber coated substrate

Liquid Permeability  Permeability helps accessibility of fluids for tissue in- growth  Instrument used for permeability: PMI Liquid Permeameter PMI Liquid Permeameter Excellent tissue in-growth in high permeable reticulated foam substrate

Mean Flow Pore Diameter  Critical flow rates and pore diameters govern tissue in- growth  Mean pore diameter measured by: PMI Capillary Flow PorometerPMI Capillary Flow Porometer  Click here for more information on this topic Click here Correlation between percent tissue in- growth and ratio of liquid permeability and mean flow pore diameter for a laser consolidated metal implant

Special Needs  You can visit our website to see the wide spectrum of pore structure capability that our instruments offervisit our website  If you have a special need that is not part of PMI’s standard test list, the engineers at PMI will be happy to talk to you about your testing requirements and come up with a suitable solution