Publications & Presentations | Mihir Madhaparia

M.S. THESISPUBLISHED 2026PROQUEST INDEXED

3D Printing of a Biocompatible Scaffold and a Real-Time Imaging Window for Monitoring Rat Spinal Cord Regeneration

Mihir A. Madhaparia

University of Minnesota – Twin Cities | Advisors: Dr. Michael C. McAlpine & Dr. Ann M. Parr

Madhaparia, M. A. (2026). 3D Printing of a Biocompatible Scaffold and a Real-Time Imaging Window for Monitoring Rat Spinal Cord Regeneration (Order No. 32443504). Dissertations and Theses at Big Ten Academic Alliance; ProQuest Dissertations and Theses Global. (3325946004).

PCL scaffold selectionPCL with 400 µm pores delivered the best balance of toughness and neural stem cell viability at 50 days post-differentiation.

In vivo imaging windowA chronic dorsal spinal imaging window was fabricated and validated in a rat model without foreign body rejection.

Structural analysisANSYS FEA validated the frame against physiological muscle loads for long-term performance.

Bioprinting comparisonComparative evaluation of EBB, SLA, MEW, inkjet, and DIW modalities for neural tissue engineering.

The development of effective regenerative therapies for spinal cord injury is hindered by two major barriers: the lack of structurally optimized bridging scaffolds and the inability to monitor biological integration in real time. This thesis addresses both challenges through a dual-objective framework.

Three scaffold materials — polycaprolactone, poly(lactic-co-glycolic acid), and silicone — were evaluated through extrusion-based direct ink writing at channel widths of 200, 400, and 600 µm. PCL with a 400 µm pore size emerged as the strongest candidate, combining surgical toughness with strong in vitro support for neural progenitor cell viability. PLGA created cytotoxic acidic microenvironments through hydrolytic degradation.

Complementing the scaffold work, a chronic dorsal spinal imaging window was designed and surgically validated in a rat model. Inspired by surgical retractors, the device used 3D-printed teeth to hold tissue open and a flush-mounted PET optical film for stable, long-term in vivo visualization.

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RESEARCH POSTERUROP

Testing the Hydrolysis-Driven Degradation of Sutures: Impacts on Tensile Strength Over Time

Mihir Madhaparia, William Durfee

Undergraduate Research Opportunities Program | University of Minnesota – Twin Cities

Hydration effectWeek 1 wetted sutures showed higher tensile strength than dry baseline, confirming short-term hydration strengthening.

Progressive lossStrength declined steadily from Week 1 through Week 4 as hydrolytic degradation increased under sustained load.

Testing protocolTesting followed ASTM D2256-02 using multiple suture sizes and a fixture simulating fascia-layer curvature.

This study evaluates the rate of tensile strength loss in sutures subjected to hydrolysis, giving surgeons data to predict wound-closure risks. Absorbable sutures degrade through hydrolysis in moisture-rich settings, and rapid degradation in spinal surgeries can contribute to wound reopening, delayed healing, and infection.

A custom degradation chamber replicated in vivo conditions using phosphate-buffered saline at 37°C with pre-tensioned loads for different suture sizes. Weekly tensile testing over five weeks followed ASTM D2256-02 standards with surgeon-prepared samples.

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SENIOR DESIGN POSTERME 4054W

Thermal Massaging Tourniquet: Venodilation Optimization Using Heat, Vibration, and Compression

Reed Benson, Alex Borsgard, Mihir Madhaparia, Gordie Straker, Sandra Turner

ME 4054W Design Projects | University of Minnesota – Twin Cities | Sponsor: Dr. Jonathan Strutt, MD

Performance gainCombined tourniquet, heat, and massage increased cephalic vein area by 67.5% versus tourniquet alone.

Optimal timing10-minute heat setting beat the 37% design target with a measured 50.9% area increase.

Safe heat rangeANSYS transient heat-transfer modeling confirmed therapeutic heating within the safe operating range.

Peripheral intravenous insertion is a common clinical procedure, but failed attempts — especially in pediatric and small-vein patients — cause pain, anxiety, and delays. Manual techniques such as massage and warming are used but not standardized or validated.

This project developed a thermal massaging tourniquet combining a tourniquet cuff, targeted vibration motors, and a heating filament above the cubital fossa. Ultrasound imaging quantified cephalic vein cross-sectional area across conditions, while transient conduction simulation informed safe temperature targets and heating duration.

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TERM PAPERME 8342MAY 2025

Convection-Driven Thermal and Mass Transfer in 3D Bioprinting: Micropore Formation and Heat Transfer in PCL and PLGA Scaffolds

Mihir Madhaparia

ME 8342: Advanced Heat Transfer | University of Minnesota – Twin Cities

Drying behaviorDrying rate changes pore size and connectivity, linking process conditions directly to scaffold architecture.

Energy balanceConnects evaporation rate to surface temperature through a coupled heat and mass-transfer framework.

Thermal performanceEffective scaffold conductivity depends on fabrication-determined porosity, linking print settings to in vivo behavior.

Extrusion-based 3D bioprinting of biodegradable polymers such as PCL and PLGA relies on solvent evaporation to generate the microporosity needed for cell infiltration and nutrient transport. This paper examines how coupled convective heat and mass transfer at the filament-air interface governs pore formation, and how that architecture influences effective thermal conductivity.

The analysis builds a coupled energy-mass balance framework in which the convective heat-transfer coefficient provides latent heat for vaporization and the mass-transfer coefficient governs vapor removal. Airflow velocity, ambient temperature, and solvent vapor concentration are identified as key process levers connecting manufacturing conditions to thermal performance.

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