Electrospray deposition (ESD) uses charged droplets at the micro- and nano-scale to create a wide... more Electrospray deposition (ESD) uses charged droplets at the micro- and nano-scale to create a wide variety of particles and coatings. In ESD, an electrostatic force is applied to a solution, which then disperses charged droplets loaded with the materials to be deposited on a grounded target. Because the droplets carry charge, repulsive effects due to accumulation of charge in a coating (self-limiting electrospray) or “crowding” of the spray droplets can reduce the efficiency of the approach. This is especially the case when the targets are smaller than the characteristic size of the spray plume. For this reason, while many studies have presumed high efficiency in ESD, the actual measured efficiencies for small targets are much lower. Here, it is shown how architecting the local “charge landscape” can lead to ESD coatings approaching 100% deposition efficiency on both flat and microneedle array targets composed of multiple model materials, including biocompatible polymers, proteins, a...
Molecular distribution in intradermal injection for transfer and delivery of therapeutics
Frontiers in Drug Delivery
Intradermal (ID) injection is a technique widely used in laboratorial and clinical applications. ... more Intradermal (ID) injection is a technique widely used in laboratorial and clinical applications. The boundary of the dome-like bleb formed during injection is assumed to represent the lateral extent of the injected material. This work systematically characterizes cargo molecule distribution (puddle) as a function of injection volume and molecular/particle size in rat skin post ID injection. In general, results indicate that the puddle forms a subdomain laterally contained within the bleb, with an area inversely correlating to the molecular size of the injected material. For 50 μL and 100 µL injections, the average area of the bleb was 40.97 ± 6.30 mm2 and 55.64 ± 8.20 mm2, respectively, regardless of the molecular/particle size. On the other hand, the area of the puddle was dependent on the molecular size and ranged between 45.38 ± 8.29 mm2 and 6.14 ± 4.50 mm2 for 50 µL injections, and 66.64 ± 11.22 mm2 and 11.50 ± 9.67 mm2 for 100 µL injections. The lateral distribution appears to ...
Immune Responses of a Novel Bi-Cistronic SARS-CoV-2 DNA Vaccine Following Intradermal Immunization With Suction Delivery
Frontiers in Virology
SARS-CoV-2 is the third pathogenic coronavirus to emerge since 2000. Experience from prior outbre... more SARS-CoV-2 is the third pathogenic coronavirus to emerge since 2000. Experience from prior outbreaks of SARS-CoV and MERS-CoV has demonstrated the importance of both humoral and cellular immunity to clinical outcome, precepts that have been recapitulated for SARS-CoV-2. Despite the unprecedented rapid development and deployment of vaccines against SARS-CoV-2, more vaccines are needed to meet global demand and to guard against immune evasion by newly emerging SARS-CoV-2 variants. Here we describe the development of pGO-1002, a novel bi-cistronic synthetic DNA vaccine that encodes consensus sequences of two SARS-CoV-2 antigens, Spike and ORF3a. Mice immunized with pGO-1002 developed humoral and cellular responses to both antigens, including antibodies and capable of neutralizing infection by a clinical SARS-CoV-2 isolate. Rats immunized with pGO-1002 by intradermal (ID) injection followed by application of suction with our GeneDerm device also developed humoral responses that included...
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Papers by Emran Lallow