Targeted allergen-specific immunotherapy within the skin improves allergen delivery to induce desensitization to peanut.

Epicutaneous immunotherapy (EPIT) with peanut has been demonstrated to be safe but efficacy may be limited by allergen uptake through the skin barrier. To enhance allergen uptake into the skin, the authors used peanut-coated microneedles and compared them with EPIT in a peanut allergy mouse model. Sensitized mice were treated with peanut-coated microneedles or peanut-EPIT and then challenged with peanut to determine protection.

Reliability and accuracy of intradermal injection by Mantoux technique, hypodermic needle adapter, and hollow microneedle in pigs.

We compared the ability of three intradermal delivery devices to administer an intended dose to pig skin in vivo and target that dose to the dermal rather than subcutaneous layers. The three devices were a standard hypodermic needle and syringe for the Mantoux technique, an adapter designed to facilitate proper hypodermic needle and syringe use, and a hollow microneedle. Reliability was determined as the percentage of the administered dose that entered the skin, as opposed to remaining in the device or on the skin surface.

In vivo high-frequency contrast-enhanced ultrasonography of choroidal melanoma in rabbits: imaging features and histopathologic correlations.

Purpose: To evaluate the use of in vivo imaging of rabbit model of choroidal melanoma using high-frequency contrast-enhanced ultrasound (HF-CE-US) with two-dimensional (2D) or three-dimensional (3D) modes and to correlate the sonographic findings with histopathologic characteristics.

Methods: Five New Zealand white rabbits, which were immunosuppressed with daily cyclosporin A (CsA), were inoculated into their right eyes with aliquots of 1.5×10(6)/50 μl of 92.

Hollow microneedles for intradermal injection fabricated by sacrificial micromolding and selective electrodeposition.

Limitations with standard intradermal injections have created a clinical need for an alternative, low-cost injection device. In this study, we designed a hollow metal microneedle for reliable intradermal injection and developed a high-throughput micromolding process to produce metal microneedles with complex geometries. To fabricate the microneedles, we laser-ablated a 70 μm × 70 μm square cavity near the tip of poly(lactic acid) (PLA) microneedles.

Targeted administration into the suprachoroidal space using a microneedle for drug delivery to the posterior segment of the eye.

Purpose: This study seeks to determine the intraocular pharmacokinetics of molecules and particles injected into the suprachoroidal space of the rabbit eye in vivo using a hollow microneedle.

Methods: Suprachoroidal injections of fluorescein and fluorescently tagged dextrans (40 and 250 kDa), bevacizumab, and polymeric particles (20 nm to 10 μm in diameter) were performed using microneedles in New Zealand white rabbits. The fluorescence intensity within the eye was monitored in each animal using an ocular fluorophotometer to determine the distribution of the injected material in the eye over time as compared with intravitreal injection of fluorescein.

In vivo ocular fluorophotometry: delivery of fluoresceinated dextrans via transscleral diffusion in rabbits.

Purpose: To evaluate the transscleral delivery of fluoresceinated dextrans (FITC-D) with molecular mass up to 70 kDa to the rabbit posterior segment using sub-Tenon injections.

Methods: Eighteen NZW rabbits received a unilateral 200-μL injection of 2 mg/mL sodium fluorescein (NaF), 25 mg/mL 40-kDa FITC-D, or 25 mg/mL 70-kDa FITC-D, with (n = 9) or without (n = 9) immediate euthanatization. In live animals, fluorescence was measured in the retina/choroid and mid-vitreous by fluorophotometry, immediately after injection and after 4, 24, 48, and 72 hours.

Mucoadhesive microparticles in a rapidly dissolving tablet for sustained drug delivery to the eye.

Purpose: To test the hypothesis that mucoadhesive microparticles formulated in a rapidly dissolving tablet can achieve sustained drug delivery to the eye.

Methods: Mucoadhesive microparticles, smaller than 5 μm were fabricated with poly(lactic-co-glycolic acid) and poly(ethylene glycol) as a core material and mucoadhesion promoter, respectively, and encapsulated pilocarpine as a model drug. These microparticles were embedded in a poly(vinyl alcohol) matrix to form a dry tablet designed to reduce rapid clearance of the microparticles on initial application to the eye.

Suprachoroidal drug delivery to the back of the eye using hollow microneedles.

Purpose: In this work, we tested the hypothesis that microneedles provide a minimally invasive method to inject particles into the suprachoroidal space for drug delivery to the back of the eye.

Methods: A single, hollow microneedle was inserted into the sclera, and infused nanoparticle and microparticle suspensions into the suprachoroidal space. Experiments were performed on whole rabbit, pig, and human eyes ex vivo.