Academic Appointments

Professional Education

  • Postdoctoral Fellow, Georgia Institute of Technology, Chemical and Biomolecular Engineering
  • PhD, Case Western Reserve University, Polymer Science and Engineering
  • MSc, Amirkabir University of Technology, Chemical Engineering
  • BSc, Sahand University of Technology, Chemical Engineering

All Publications

  • Dependence on relative humidity in the formation of reactive oxygen species in water droplets. Proceedings of the National Academy of Sciences of the United States of America Mofidfar, M., Mehrgardi, M. A., Xia, Y., Zare, R. N. 2024; 121 (12): e2315940121


    Water microdroplets (7 to 11 µm average diameter, depending on flow rate) are sprayed in a closed chamber at ambient temperature, whose relative humidity (RH) is controlled. The resulting concentration of ROS (reactive oxygen species) formed in the microdroplets, measured by the amount of hydrogen peroxide (H2O2), is determined by nuclear magnetic resonance (NMR) and by spectrofluorimetric assays after the droplets are collected. The results are found to agree closely with one another. In addition, hydrated hydroxyl radical cations (•OH-H3O+) are recorded from the droplets using mass spectrometry and superoxide radical anions (•O2-) and hydroxyl radicals (•OH) by electron paramagnetic resonance spectroscopy. As the RH varies from 15 to 95%, the concentration of H2O2 shows a marked rise by a factor of about 3.5 in going from 15 to 50%, then levels off. By replacing the H2O of the sprayed water with deuterium oxide (D2O) but keeping the gas surrounding droplets with H2O, mass spectrometric analysis of the hydrated hydroxyl radical cations demonstrates that the water in the air plays a dominant role in producing H2O2 and other ROS, which accounts for the variation with RH. As RH increases, the droplet evaporation rate decreases. These two facts help us understand why viruses in droplets both survive better at low RH values, as found in indoor air in the wintertime, and are disinfected more effectively at higher RH values, as found in indoor air in the summertime, thus explaining the recognized seasonality of airborne viral infections.

    View details for DOI 10.1073/pnas.2315940121

    View details for PubMedID 38489384

  • One-step Formation of Urea from Carbon Dioxide and Nitrogen Using Water Microdroplets. Journal of the American Chemical Society Song, X., Basheer, C., Xia, Y., Li, J., Abdulazeez, I., Al-Saadi, A. A., Mofidfar, M., Suliman, M. A., Zare, R. N. 2023


    Water (H2O) microdroplets are sprayed onto a graphite mesh covered with a CuBi2O4 coating using a 1:1 mixture of N2 and CO2 as the nebulizing gas. The resulting microdroplets contain urea [CO(NH2)2] as detected by both mass spectrometry and 13C nuclear magnetic resonance. This gas-liquid-solid heterogeneous catalytic system synthesizes urea in one step on the 0.1 ms time scale. The conversion rate reaches 2.7 mmol g-1 h-1 at 25 °C and 12.3 mmol g-1 h-1 at 65 °C, with no external voltage applied. Water microdroplets serve as the hydrogen source and the electron transfer medium for N2 and CO2 in contact with CuBi2O4. Water-gas and water-solid contact electrification are speculated to drive the reaction process. This strategy couples N2 fixation and CO2 utilization in an ecofriendly process to produce urea, converting a greenhouse gas into a value-added product.

    View details for DOI 10.1021/jacs.3c10784

    View details for PubMedID 37966066

  • Therapeutic contact lenses for the treatment of corneal and ocular surface diseases: advances in extended and targeted drug delivery. International journal of pharmaceutics Abdi, B., Mofidfar, M., Hassanpour, F., Kirbas Cilingir, E., Kalajahi, S. K., Milani, P. H., Ghanbarzadeh, M., Fadel, D., Barnett, M., Ta, C. N., Leblanc, R. M., Chauhan, A., Abbasi, F. 2023: 122740


    The eye is one of the most important organs in the human body providing critical information on the environment. Many corneal diseases can lead to vision loss affecting the lives of people around the world. Ophthalmic drug delivery has always been a major challenge in the medical sciences. Since traditional methods are less efficient ( 5%) at delivering drugs to ocular tissues, contact lenses have generated growing interest in ocular drug delivery due to their potential to enhance drug bioavailability in ocular tissues. The main techniques used to achieve sustained release are discussed in this review, including soaking in drug solutions, incorporating drug into multilayered contact lenses, use of vitamin E barriers, molecular imprinting, nanoparticles, micelles and liposomes. The most clinically relevant results on different eye pathologies are presented. In addition, this review summarizes the benefits of contact lenses over eye drops, strategies for incorporating drugs into lenses to achieve sustained release, results of in vitro and in vivo studies, and the recent advances in the commercialization of therapeutic contact lenses for allergic conjunctivitis.

    View details for DOI 10.1016/j.ijpharm.2023.122740

    View details for PubMedID 36804524

  • Silicone Wristband Spray Ionization Mass Spectrometry for Combined Exposome and Metabolome Profiling ISRAEL JOURNAL OF CHEMISTRY Mofidfar, M., Song, X., Kelly, J. T., Rubenstein, M. H., Zare, R. N. 2023
  • On-demand electrochemically controlled compound release from an ultrasonically powered implant RSC ADVANCES Wang, M. L., Chamberlayne, C. F., Xu, H., Mofidfar, M., Baltsavias, S., Annes, J. P., Zare, R. N., Arbabian, A. 2022; 12 (36): 23337-23345

    View details for DOI 10.1039/d2ra03422k

    View details for Web of Science ID 000841167500001

  • Capturing Reactive Carbanions by Microdroplets. Journal of the American Chemical Society Kumar, A., Mondal, S., Mofidfar, M., Zare, R. N., Banerjee, S. 2022


    Carbanions appear in many organic or biological reactions as fleeting intermediates, prohibiting direct observation or spectroscopic measurement. An aqueous environment is known to rapidly annihilate a carbanion species, reducing its lifetime to as short as picoseconds. We report that aqueous microdroplets can capture and stabilize reactive carbanion intermediates isolated from four classic organic reactions, aldol and Knoevenagel condensations, alkyne alkylation, and the Reimer-Tiemann reaction, enabling the detection of their carbanion intermediates by desorption electrospray ionization mass spectrometry. This is accomplished in real time of the reaction, allowing new insights into reaction mechanisms to be obtained. The efficacy of microdroplets in capturing such elusive species was examined by varying the solvent and the microdroplet negative charge density. We observed that microdroplets composed of water-methanol outperform other solvents, such as pure water, in capturing carbanions, which is in contrast to the earlier report that presented the highest performance of pure water microdroplets in capturing carbocations. We offer some mechanistic insights to explain the discriminatory behavior of these two oppositely charged species in microdroplets.

    View details for DOI 10.1021/jacs.2c01577

    View details for PubMedID 35452233

  • Sprayed Water Microdroplets Are Able to Generate Hydrogen Peroxide Spontaneously. Journal of the American Chemical Society Mehrgardi, M. A., Mofidfar, M., Zare, R. N. 2022


    Ultrapure N2 gas was bubbled through water, and the humidified output containing undetectable concentrations of ozone filled a closed chamber in which 18 MOmega-cm water was sprayed through a silica capillary to form microdroplets. Analysis of the collected microdroplets by NMR spectroscopy showed the presence of hydrogen peroxide at a concentration level ranging from 0.3 to 1.5 muM depending on the flow conditions. This was confirmed using a spectrofluorometric assay. We suggest that this finding establishes that when sprayed to form microdroplets, water has the ability to produce hydrogen peroxide by itself. When the N2 gas is replaced by compressed air or O2 gas, the concentration of hydrogen peroxide is found to increase, indicating that gas-surface interactions with O2 in aqueous microdroplets promote the formation of hydrogen peroxide.

    View details for DOI 10.1021/jacs.2c02890

    View details for PubMedID 35451822

  • Antimicrobial Activity of Silver Containing Crosslinked Poly(Acrylic Acid) Fibers MICROMACHINES Mofidfar, M., Kim, E., Larkin, E. L., Long, L., Jennings, W. D., Ahadian, S., Ghannoum, M. A., Wnek, G. E. 2019; 10 (12)


    : Bacterial and fungal pathogens have caused serious problems to the human health. This is particularly true for untreatable infectious diseases and clinical situations where there is no reliable treatment for infected patients. To increase the antimicrobial activity of materials, we introduce silver nanoparticle (NP) patches in which the NPs are incorporated to the surface of smooth and uniform poly(acrylic acid) (PAA) nanofibers. The PAA nanofibers were thermally crosslinked with ethylene glycol via heat treatment through a mild method. The characterization of the resulting PAA-silver NP patches was done using scanning electron microscopy (SEM), UV spectroscopy, X-ray diffraction (XRD), and X-ray photoelectron spectroscopy (XPS). To demonstrate the antimicrobial activity of PAA, we incorporated the patches containing the silver NPs into strains of fungi such as Candida albicans (C. albican) and bacteria such as Methicillin-resistant Staphylococcus aureus (MRSA). The PAA-silver fibers achieved zones of inhibition against C. albicans and MRSA indicating their antimicrobial activity against both fungi and bacteria. We conclude that silver NP patches exhibited multiple inhibitory actions for the interruption and blockage of activity fungal and bacterial strains, which has the potential as an antimicrobial agent in infectious diseases. Moreover, the proposed material has the potential to be used in antimicrobial textile fabrics, food packaging films, and wound dressings.

    View details for DOI 10.3390/mi10120829

    View details for Web of Science ID 000507337900017

    View details for PubMedID 31795271

    View details for PubMedCentralID PMC6953080

  • Pharmaceutical jewelry: Earring patch for transdermal delivery of contraceptive hormone JOURNAL OF CONTROLLED RELEASE Mofidfar, M., O'Farrell, L., Prausnitz, M. R. 2019; 301: 140-145


    Lack of adherence to medication dosing schedules is a significant cause of morbidity and mortality with large associated financial costs. This is especially true for contraceptive hormones, which provide almost perfect prevention of pregnancy when used correctly, but have significant failure rates in typical use, due largely to poor adherence. To increase medication acceptability and adherence, we introduce pharmaceutical jewelry, in which a transdermal patch is incorporated into jewelry worn on skin. To demonstrate the approach, we incorporated transdermal patches containing the contraceptive hormone levonorgestrel (LNG) into an earring, a ring, a necklace, and a wrist watch. Transdermal delivery of LNG from earring patches across porcine skin ex vivo achieved a steady state flux of 1.7 μg/cm2·h. Pharmacokinetic analysis in hairless rats yielded LNG delivery rates that maintained serum LNG levels near 1500 pg/ml throughout the 1-week patch application period, which is well above the human contraceptive threshold concentration of 200 pg/ml. When patches were applied cyclically for 16 h on and 8 h off to simulate earring removal at night, serum LNG concentrations dipped during off periods, but remained well above the human contraceptive threshold. Earring patches were well tolerated by the rats. We conclude that pharmaceutical jewelry can provide a novel method of drug delivery, especially for contraceptive hormones, that has the potential to improve acceptability and increase medication adherence.

    View details for DOI 10.1016/j.jconrel.2019.03.011

    View details for Web of Science ID 000466361500011

    View details for PubMedID 30876952

  • Electrospun Transdermal Patch for Contraceptive Hormone Delivery CURRENT DRUG DELIVERY Mofidfar, M., Prausnitz, M. R. 2019; 16 (6): 577-583


    A transdermal patch for delivery of Levonorgestrel (LNG) can be used for long-acting contraception.In this study, we designed and characterized a patch made of nonwoven electrospun microfibers comprised of Polycaprolactone (PCL) encapsulating LNG for slow release in a mineral oil matrix.Scanning electron microscopy showed uniform, randomly oriented PCL fibers with large interconnected voids filled with mineral oil. Thermogravimetric analysis indicated that LNG loaded into PCL fibers had thermal stability up to ~200°C. Differential Scanning Calorimetry suggested that LNG was dispersed in the electrospun fibers without interaction between the LNG and PCL, and without formation of drug crystals. Fourier Transform Infrared spectroscopy and X-ray diffraction results further supported the conclusion that there was no chemical drug-polymer interaction in LNGloaded fibers. Effective in vitro flux (i) from patches into mineral oil was 1.9 µgcm-2h-1, (ii) from mineral oil across porcine skin was 4.6 µgcm-2h-1 and (iii) from patches across porcine skin was 1.7 μgcm- 2h-1, indicating that transdermal delivery rate was controlled by a combination of the patch and the skin.The LNG-loaded patches demonstrated steady delivery of LNG across skin for up to 5 days in vitro. With additional development, LNG-loaded electrospun PCL patches could be used for long-acting contraception.

    View details for DOI 10.2174/1567201816666190308112010

    View details for Web of Science ID 000483386900009

    View details for PubMedID 30848203

  • Polymeric Nanofiber/Antifungal Formulations Using a Novel Co-extrusion Approach AAPS PHARMSCITECH Mofidfar, M., Wang, J., Long, L., Hager, C. L., Vareechon, C., Pearlman, E., Baer, E., Ghannoum, M., Wnek, G. E. 2017; 18 (6): 1917-1924


    We report the successful implementation of a novel melt co-extrusion process to fabricate ca. 1 μm diameter fibers of poly(caprolactone) (PCL) containing the antifungal compound clotrimazole in concentrations between 4 and 8 wt%. The process involves co-extrusion of a clotrimazole-loaded PCL along with poly(ethylene oxide) (PEO) as a co-feed, with subsequent removal of PEO to isolate PCL-clotrimazole fibers. In vitro tests of the clotrimazole-containing fibers against the fungus Aspergillus fumigatus, Candida albicans, and Trichophyton mentagrophytes strains demonstrated good antifungal activity which was maintained for more than 3 weeks. An in vivo study using a mouse model showed the lowest tissue fungal burden for PCL-clotrimazole when compared to a PCL-only patch and untreated controls. Comparative studies were conducted with clotrimazole-containing PCL fibers fabricated by electrospinning. Our data showed that the co-extruded, clotrimazole-containing fibers maintain activity for longer times vs. electrospun samples. This, coupled with the much higher throughput of the co-extrusion process vs. electrospinning, renders this new approach very attractive for the fabrication of drug-releasing polymer fibers.

    View details for DOI 10.1208/s12249-016-0664-2

    View details for Web of Science ID 000406652000003

    View details for PubMedID 27858252