Preclinical evaluation of performance, safety and usability of VAX-ID®, a novel intradermal injection device.

The recent SARS-Cov2 pandemic and mpox health emergency have led to renewed interest in intradermal vaccination due to its dose sparing potential. Indeed, intradermal vaccination is particularly of interest for use in mass vaccination campaigns, pandemic preparedness programs, and/or for vaccines that are expensive or in short supply. Moreover, the rich immune network in the skin makes it an attractive target not only for prophylactic vaccination, but also for therapeutic vaccination, like immunotherapy and (dendritic) cell-based therapies. The aim of the current paper was to provide an overview of preclinical data generated with VAX-ID®, a novel intradermal drug delivery device, to allow assessing it performance, safety and usability. The device can overcome challenges seen with the Mantoux technique whereby the needle needs to be inserted under a shallow angle. Various parameters of VAX-ID® were evaluated, including dead-space volume, dose accuracy, penetration depth & liquid deposit in piglets, as well as usability by healthcare professionals. The device has shown to have a low dead volume and a high dose accuracy. Importantly, the device performed successful injections at a predefined depth into the dermis with a high safety profile as confirmed by visual and histological evaluation in piglets. Moreover, the device was rated as easy to use by healthcare professionals. The combined preclinical performance and usability findings indicate that VAX-ID® can provide reliable, standardized and accurate drug delivery in the dermal layer of the skin with a high ease of use. The device offers a solution for injection of various prophylactic as well as therapeutic vaccines.

The immunological effects of intradermal particle-based vaccine delivery using a novel microinjection needle studied in a human skin explant model.

For intradermal (ID) immunisation, novel needle-based delivery systems have been proposed as a better alternative to the Mantoux method. However, the penetration depth of needles in the human skin and its effect on immune cells residing in the different layers of the skin has not been analyzed. A novel and user-friendly silicon microinjection needle (Bella-muTM) has been developed, which allows for a perpendicular injection due to its short needle length (1.4-1.8 mm) and ultrashort bevel. We aimed to characterize the performance of this microinjection needle in the context of the delivery of a particle-based outer membrane vesicle (OMV) vaccine using an ex vivo human skin explant model. We compared the needles of 1.4 and 1.8 mm with the conventional Mantoux method to investigate the depth of vaccine injection and the capacity of the skin antigen-presenting cell (APC) to phagocytose the OMVs. The 1.4 mm needle deposited the antigen closer to the epidermis than the 1.8 mm needle or the Mantoux method. Consequently, activation of epidermal Langerhans cells was significantly higher as determined by dendrite shortening. We found that five different subsets of dermal APCs are able to phagocytose the OMV vaccine, irrespective of the device or injection method. ID delivery using the 1.4 mm needle of a OMV-based vaccine allowed epidermal and dermal APC targeting, with superior activation of Langerhans cells. This study indicates that the use of a microinjection needle improves the delivery of vaccines in the human skin.

Programmable and monitorable intradermal vaccine delivery using ultrasound perforation array.

Skin disruptions of micrometer- or submillimeter-diameter generated by microneedle or laser ablation can be used for intradermal vaccination. Here, we report a new skin-disruption method that uses highly-focused ultrasound to controllably perforate murine skin. We showed that programming of ultrasound parameters varied skin perforation area from 0.078 ± 0.045 mm2 to 1.295 ± 0.279 mm2. The skin perforation area increased with increasing ultrasound pressure and exposure time, and decreased with increasing ultrasound frequency and incidence angle. Moreover, successful perforation can be monitored using ultrasound pulse-echo imaging. We found that ultrasound perforation elevated local skin expression of heat shock protein 70 and effectively attracted MHC II-positive immune cells after intradermal delivery of Hepatitis B surface antigen (HBsAg). We demonstrated that the antigen dose delivered by ultrasound perforation can be effectively modulated via programmable perforation arrays (comprised of 1 × 2, 1 × 3, 1 × 5 or 3 × 3 areas of exposure). Using a 1 × 3 perforation array for vaccination, the measured mean optical density (OD) value of serum anti-HBsAg IgG was slightly higher than that of intradermal injection. The addition of an adjuvant of recombinant cholera toxin B further increased OD values of anti-HBsAg IgG. This ultrasound perforation method holds great promise for monitorable and programmable intradermal vaccination.

Performance and usability evaluation of novel intradermal injection device Immucise™ and reanalysis of intradermal administration trials of influenza vaccine for the elderly.

Under the pandemic situation, there is an urgent need to produce and acquire sufficient quantities of prophylactic vaccines. It becomes important to devise a way to achieve reliable immunity with lower doses to distribute limited supplies of vaccines to maximum number of people very quickly. Intradermal (ID) vaccination is one such method to increase the effectiveness of vaccines. However, this method has not been widely used in general clinical practice because it is technically difficult to inject vaccines precisely into the ID tissue. Therefore, new ID delivery systems that allow reliable ID administration are under development. In this paper, we summarize its design and present the results of performance and usability testing for the Immucise™ Intradermal Injection System (Immucise™). This study showed that Immucise™ can reduce dead volume and inject drugs precisely into the ID tissues of subjects from infants to the elderly and can be used correctly and safely by healthcare professionals. This randomized controlled trial compared ID administration with Immucise™ and standard subcutaneous (SC) administration of seasonal influenza vaccine by analyzing the efficacy of the vaccine in the elderly group at 90 days and 180 days after administration. It was found that the vaccine for the ID group was as effective or more effective than that for the SC group up to 180 days later. It was also found that the geometric mean titer values, especially for B strains, were higher in the two-dose ID group than in the two-dose SC group. These findings suggest that Immucise™ is one of the best devices to distribute a small amount of vaccine quickly and widely to a larger number of people with little loss of vaccine during a pandemic.

Comparison of lymphatic contrast-enhanced ultrasound and intravenous contrast-enhanced ultrasound in the preoperative diagnosis of axillary sentinel lymph node metastasis in patients with breast cancer.

OBJECTIVES: This study aimed to compare diagnostic efficiency for axillary sentinel lymph node (SLN) metastasis between lymphatic contrast-enhanced ultrasound (LCEUS) and intravenous contrast-enhanced ultrasound (ICEUS) in patients with breast cancer. We also examined whether adding ICEUS to LCEUS could improve the diagnostic accuracy of LCEUS. METHODS: Sixty-nine patients with breast cancer were recruited preoperatively. All patients underwent LCEUS followed by ICEUS, and the enhancement pattern of one SLN was analysed for each patient. The targeted SLN was marked with wire and excised during surgery. The imaging diagnosis was compared with the histopathological result. Diagnostic efficiency was compared among LCEUS, ICEUS, and the combination of LCEUS and ICEUS. RESULTS: The sensitivity values for LCEUS, ICEUS, and the combination of LCEUS and ICEUS were 86.2%, 82.6% and 93.1%, respectively. Specificity values for the three methods were 95.0%, 92.5% and 87.5%, respectively. Accuracy values for the three methods were 91.3%, 88.4% and 89.9%, respectively. The area under the receiver operating characteristic (ROC) curve for LCEUS was 0.906, and there was no significant difference among LCEUS, ICEUS, and the combination of LCEUS and ICEUS (p = 0.752). CONCLUSIONS: LCEUS may represent an accurate method for predicting SLN metastasis preoperatively. Our findings suggest that adding ICEUS to LCEUS for SLN evaluation in patients with breast cancer is unnecessary. ADVANCES IN KNOWLEDGE: This is the first study in which both LCEUS and ICEUS were performed for the same lymph node and the first to compare the diagnostic efficiency of LCEUS, ICEUS, and the combination of LCEUS + ICEUS.

Epicutaneous Allergen Administration with Microneedles as a Novel Method of Immunotherapy for House Dust Mite (HDM) Allergic Rhinitis.

PURPOSE: Epicutaneous immunotherapy (EPIT) is being studied as a method for treating allergic rhinitis because of skin immunology, user convenience and enhanced patient compliance. However, the use of EPIT is limited because of the very low skin permeability of the allergen. In this study, the limitations of EPIT were overcome by using sophisticated delivery with microneedles. The immunological efficacy of this method was studied in a murine model of house dust mite (HDM) allergic rhinitis. METHODS: The length of the microneedles was 400 µm, and the coating formulation containing HDM was locally distributed near the end of the microneedle tips. The change of distribution of FITC-dextran in porcine skin in vitro was observed over time using a confocal microscope. The effect of immunotherapy in the allergic rhinitis model, sensitized by HDM-coated microneedles (HDM MNs), was observed according to the amount of HDM applied. RESULTS: The microneedles delivered the coating formulation with precision into the porcine skin layer, and the coated formulation on the microneedles was all dissolved in the porcine skin in vitro within 20 min of administration and then gradually diffused into the skin layer. When HDM MNs were administered to mice, a 0.1-µg dose of HDM provided the most effective immunization, and improved efficacy was shown between 0.1- and 0.5- µg doses of HDM. CONCLUSIONS: Effective immunotherapy can be achieved by precision delivery of the allergen into the skin layer, and microneedles can provide effective immunological therapy by delivering the appropriate amount of allergen.

Bleomycin administered by laser-assisted drug delivery or intradermal needle-injection results in distinct biodistribution patterns in skin: in vivo investigations with mass spectrometry imaging.

Bleomycin (BLM) is being repositioned in dermato-oncology for intralesional and intra-tumoural use. Although conventionally administered by local needle injections (NIs), ablative fractional lasers (AFLs) can facilitate topical BLM delivery. Adding local electroporation (EP) can augment intracellular uptake in the target tissue. Here, we characterize and compare BLM biodistribution patterns, cutaneous pharmacokinetic profiles, and tolerability in an in vivo pig model following fractional laser-assisted topical drug delivery and intradermal NI, with and without subsequent EP. In vivo pig skin was treated with AFL and topical BLM or NI with BLM, alone or with additional EP, and followed for 1, 2 and 4 h and eventually up to 9 d. BLM biodistribution was assessed by spatiotemporal mass spectrometry imaging. Cutaneous pharmacokinetics were assessed by mass spectrometry quantification and temporal imaging. Tolerability was evaluated by local skin reactions (LSRs) and skin integrity measurements. AFL and NI resulted in distinct BLM biodistributions: AFL resulted in a horizontal belt-shaped BLM distribution along the skin surface, and NI resulted in BLM radiating from the injection site. Cutaneous pharmacokinetic analyses and temporal imaging showed a substantial reduction in BLM concentration within the first few hours following administration. LSRs were tolerable overall, and all interventions permitted almost complete recovery of skin integrity within 9 d. In conclusion, AFL and NI result in distinct cutaneous biodistribution patterns and pharmacokinetic profiles for BLM applied to in vivo skin. Evaluation of LSRs showed that both methods were similarly tolerable, and each method has potential for individualized approaches in a clinical setting.

Induction of Humoral and Cellular Immunity by Intradermal Delivery of SARS-CoV-2 Nucleocapsid Protein Using Dissolvable Microneedles.

The nucleocapsid protein (NP) of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) contains immunogenic epitopes that can induce cytotoxic T lymphocyte (CTL) against viral infection. This makes the nucleocapsid protein a suitable candidate for developing a vaccine against SARS-CoV-2 infection. This article reports the intradermal delivery of NP antigen using dissolvable microneedle skin patches that could induce both significant B cell and T cell responses.

Clustering and Erratic Movement Patterns of Syringe-Injected versus Mosquito-Inoculated Malaria Sporozoites Underlie Decreased Infectivity.

Malaria vaccine candidates based on live, attenuated sporozoites have led to high levels of protection. However, their efficacy critically depends on the sporozoites' ability to reach and infect the host liver. Administration via mosquito inoculation is by far the most potent method for inducing immunity but highly impractical. Here, we observed that intradermal syringe-injected Plasmodium berghei sporozoites (syrSPZ) were 3-fold less efficient in migrating to and infecting mouse liver than mosquito-inoculated sporozoites (msqSPZ). This was related to a clustered dermal distribution (2-fold-decreased median distance between syrSPZ and msqSPZ) and, more importantly, a 1.4-fold (significantly)-slower and more erratic movement pattern. These erratic movement patterns were likely caused by alteration of dermal tissue morphology (>15-µm intercellular gaps) due to injection of fluid and may critically decrease sporozoite infectivity. These results suggest that novel microvolume-based administration technologies hold promise for replicating the success of mosquito-inoculated live, attenuated sporozoite vaccines.IMPORTANCE Malaria still causes a major burden on global health and the economy. The efficacy of live, attenuated malaria sporozoites as vaccine candidates critically depends on their ability to migrate to and infect the host liver. This work sheds light on the effect of different administration routes on sporozoite migration. We show that the delivery of sporozoites via mosquito inoculation is more efficient than syringe injection; however, this route of administration is highly impractical for vaccine purposes. Using confocal microscopy and automated imaging software, we demonstrate that syringe-injected sporozoites do cluster, move more slowly, and display more erratic movement due to alterations in tissue morphology. These findings indicate that microneedle-based engineering solutions hold promise for replicating the success of mosquito-inoculated live, attenuated sporozoite vaccines.

Intradermal Microdroplet Injection of Diluted Incobotulinumtoxin-A for Sebum Control, Face Lifting, and Pore Size Improvement.

BACKGROUND: Intradermal injections of botulinum toxin have been reported to improve sebum secretion, facial skin laxity, and facial pores. However, the effects of Incobotulinumtoxin-A for these indications have not been reported. OBJECTIVE: To evaluate the efficacy of Incobotulinumtoxin-A for the improvement of sebum secretion, face laxity, and facial pores. MATERIALS AND METHODS: This single-center retrospective study included patients treated with Incobotulinumtoxin-A to improve facial skin laxity, sebum secretion, and facial pores. The microdroplet injection protocol included injection points on the lateral face, anterior medial cheek, mandibular line, depressor anguli oris points, mid-glabella area, and chin. Outcomes were measured using a Sebumeter and three-dimensional scanner and were evaluated by facial laxity ratings and the Global Aesthetic Improvement Scale. RESULTS: Twenty patients were included in the analysis. Sebum secretion, mandibular length, facial pores, and facial laxity ratings were improved at 1 week and results were sustained through 12 weeks. All outcomes showed maximum improvement after 4 weeks. Evaluation using the Global Aesthetic Improvement Scale showed that all subjects reported at least a score of 2 (improved) after 4 weeks. CONCLUSION: This study showed that intradermal injection with Incobotulinumtoxin-A could be effective for face lifting, reduced sebum production, and improved facial pores. J Drugs Dermatol. 2021;20(1):49-54. doi:10.36849/JDD.5616.

Granulomas and nongranulomatous nodules after filler injection: Different complications require different treatments.

Dermal fillers are widely used for facial rejuvenation and reconstruction and present fewer risks than surgical approaches. Nevertheless, several complications may occur, including nodule formation. A nodule is a clinical sign corresponding to different etiologies, such as overcorrection, infection, allergic reaction, or granuloma. However, their treatment represents a diagnostic challenge. We present a retrospective review of 26 consecutive patients who underwent a biopsy for facial nodule formation more than 3 months after filler injections, to determine the diagnosis of the nodule and type of filler used. All patients were women (mean age, 57.8 years). Some patients suffered from different localizations: lip, 14 cases; nasolabial folds, 6; cheeks, 5; infraorbital region, 5; the glabella, 2; the temporal region, 1; and chin, 1 case. Only 5 (19.2%) patients knew the type of filler used, and in another 4 cases, the injector was able to provide some information. In 65.4% of cases, the filler type was unknown. Histopathological analysis revealed a "granulomatous" nodule in 30 sites and a "non-granulomatous" nodule in 4 cases. Concerning the type of filler, 5 different histopathological patterns were found. Our results demonstrate that a clinical history and histopathological analysis whether to confirm or not to confirm the diagnosis of granuloma and to identify the type of filler are essential tools to achieve an accurate diagnosis of the problem-oriented treatment of nodules after dermal filler injections. We propose an algorithm for the management of nodules after filler injection.

Patchless administration of canine influenza vaccine on dog's ear using insertion-responsive microneedles (IRMN) without removal of hair and its in vivo efficacy evaluation.

Microneedles provide the advantages of convenience and compliance by avoiding the pain and fear of needles that animals often experience. Insertion-responsive microneedles (IRMN) were used for administration to a hairy dog without removing the dog's hair. Canine H3N2 vaccine was administered with IRMN attached to the dog's ears ex vivo and the conventional microneedle system (MN) was administered for 15 min to compare puncture performance and delivery efficiency. The vaccine was also administered to compare antibody formation using IRMN with the use of intramuscular injection. The veterinarian observed the behavior of the dog during the course of the administration and compared the response to IRMN with that of intramuscular administration. The tips of IRMN were separated from the base and delivered into the hairy skin successfully. Puncture performance of IRMN were the same as that of coated microneedles (95%), but delivery efficiency of IRMN were 95% compared to less than 1% for coated microneedles. The H3N2 vaccine inoculated into the dog's ears showed the same antibody formation as the intramuscular injection. The dog appeared to be more comfortable with IRMN administration compared to syringe administration. IRMN are the first microneedle system to deliver a canine vaccine successfully into a hairy dog without removal of the dog's hair. The use of IRMN can provide both convenience and compliance for both the dog and the owner.

Study of efficacy of microneedling and mesoneedling in the treatment of epidermal melasma: A pilot trial.

BACKGROUND: Melasma is a difficult to treat pigmentation disorder. However, some successes have been attained by microneedling. The aim of the present study was to evaluate the efficacy of microneedling using meso-depigmentation solution (mesoneedling) in comparison with standard microneedling, over a 4-month treatment period. METHODS: As a part of this pilot study, 20 patients received microneedling on one side and mesoneedling on another side of their face. Treatment was repeated on a monthly basis for 4 months. Treatment efficacy was defined through Dermacatch® colorimetry, modified Melasma Area and Severity (mMASI) score determination, Investigator's Global Assessment (IGA), and patient questionnaires, whereby all assessments were conducted at the baseline, as well after 2 and 4 months of treatment. RESULTS: Before treatments, mean difference between pigmented and normal skin calculated by Dermacatch® was 43.7 ± 20.12 and 44.6 ± 20.72 in microneedling sides and mesoneedling sides, respectively. After two and four sessions, these values declined to 34.5 ± 16.26 and 28.05 ± 13.79 on the side subjected to microneedling, while 29.75 ± 15.07 and 20.45 ± 10.58 were measured on the mesoneedling side. Statistically significant differences have been observed between microneedling and mesoneedling treatments at both time points (P = .0001, P = .0001). The mMASI scores obtained upon treatment completion were significantly lower on both the microneedling and the mesoneedling side. The IGA and patients' self-assessment scores further confirmed that both treatments were effective in treating melasma, without producing any notable side-effects or complications. CONCLUSION: In sum, both microneedling and mesoneedling are effective in decreasing melanin content in the epidermal melasma lesions.

Preinjection aspiration for injectable fillers in aesthetic dermatology: Trust or bust?

In recent years, the utility of preinjection aspiration for injectable fillers as a safety checkpoint has been debated. It is a clinical technique that has become controversial in both the literature and at national aesthetic conferences. Many consensus papers and anecdotal reports have been divided on how helpful preinjection aspiration is in reducing adverse events and subsequently increasing patient safety. Here, we summarize the prominent studies in the literature and offer an evaluation and insights.

Diphtheria toxoid dissolving microneedle vaccination: Adjuvant screening and effect of repeated-fractional dose administration.

In this study the effect of repeated-fractional intradermal administration of diphtheria toxoid (DT) compared to a single administration in the presence or absence of adjuvants formulated in dissolving microneedles (dMNs) was investigated. Based on an adjuvant screening with a hollow microneedle (hMN) system, poly(I:C) and gibbsite, a nanoparticulate aluminum salt, were selected for further studies: they were co-encapsulated with DT in dMNs with either a full or fractional DT-adjuvant dose. Sharp dMNs were prepared regardless the composition and were capable to penetrate the skin, dissolve within 20 min and deposit the intended antigen-adjuvant dose, which remained in the skin for at least 5 h. Dermal immunization with hMN in repeated-fractional dosing (RFrD) resulted in a higher immune response than a single-full dose (SFD) administration. Vaccination by dMNs led overall to higher responses than hMN but did not show an enhanced response after RFrD compared to a SFD administration. Co-encapsulation of the adjuvant in dMNs did not increase the immune response further. Immunization by dMNs without adjuvant gave a comparable response to subcutaneously injected DT-AlPO4 in a 15 times higher dose of DT, as well as subcutaneous injected DT-poly(I:C) in a similar DT dose. Summarizing, adjuvant-free dMNs showed to be a promising delivery tool for vaccination performed in SFD administration.

Mussel-Inspired Polydopamine Coating Enhances the Intracutaneous Drug Delivery from Nanostructured Lipid Carriers Dependently on a Follicular Pathway.

Inspired by the structure and function of the mussel adhesive protein, a facile strategy involving oxidative polymerization of dopamine was proposed for surface modification of nanostructured lipid carriers (NLCs) to promote drug delivery in the skin. The formation of a polydopamine (PDA) layer rounding the surface of NLCs was confirmed by the X-ray photoelectron spectroscopy and the Fourier transform infrared spectroscopy studies. Using terbinafine (TBF) as a model drug, the in vitro permeation study revealed that the PDA coating significantly enhanced the delivery of TBF from NLCs to the deep skin layers, where the follicular pathway played an essential role as suggested by the hair follicle blocking and differential tape stripping experiments, as well as the laser scanning confocal microscopy study by using Nile red as the fluorescent probe. The cellular investigation indicated that the PDA coating led to a higher cellular uptake of nanoparticles in human immortalized keratinocytes (HaCaT) without causing additional cytotoxicity. Using endocytic inhibitors, it was found that the lipid raft/caveolae-mediated endocytosis was strongly involved in the internalization of both the PDA modified and unmodified NLCs. Our results suggested that surface modification of NLCs with PDA coating improved the intracutaneous drug delivery mainly via the follicular pathway, which provided an avenue for the development of potential drug delivery carriers for dermal use.

No effect of inoculation site and injection device on the skin test response of red deer to the intradermal injection of Mycobacterium avium-derived purified protein derivative (PPD).

Mycobacterial diseases are important health issues in farmed deer. The single intradermal tuberculin test is the standard test for tuberculosis testing in deer. We studied two factors which might influence the response of deer to skin testing: the inoculation site and the injection device. Deer included in this study were 2.5 years old farmed red deer (Cervus elaphus) hinds (n = 80). Two areas of 3 cm × 3 cm were shaved at the left side of the neck. Site A (SA) was situated about 10 cm caudal to the head, while site B (SB) was 10 cm caudal to SA. All hinds received at the same time two 0.1 ml inoculations of Mycobacterium avium derived purified protein derivative (aPPD). One inoculation was made by syringe and the other one with the needle-free syringe Dermojet. To test the inoculation site effect, half of the animals were inoculated by Dermojet in SA and by syringe in SB to compare with the inoculation in SA by syringe and Dermojet in SB in the other half. No differences were recorded for the injection device nor for the inoculation site. Ten hinds had a skinfold increase larger than 30 tenths of mm by any injection device and inoculation site. Seven (9%) and 6 (8%) hinds were classified as positive by syringe and Dermojet, and at the anterior or posterior inoculation site, respectively. The distribution of skinfold thickness increases did not differ by injection device. Our findings support the needle-free Dermojet syringe as a suitable tool for skin-testing in red deer and suggest no relevant effect of the position of the inoculation site along the neck in red deer.