Improving dermal fibroblast-to-epidermis communications and aging wound repair through extracellular vesicle-mediated delivery of Gstm2 mRNA.

Skin aging is characterized by the disruption of skin homeostasis and impaired skin injury repair. Treatment of aging skin has long been limited by the unclear intervention targets and delivery techniques. Engineering extracellular vesicles (EVs) as an upgraded version of natural EVs holds great potential in regenerative medicine. In this study, we found that the expression of the critical antioxidant and detoxification gene Gstm2 was significantly reduced in aging skin. Thus, we constructed the skin primary fibroblasts-derived EVs encapsulating Gstm2 mRNA (EVsGstm2), and found that EVsGstm2 could significantly improve skin homeostasis and accelerate wound healing in aged mice. Mechanistically, we found that EVsGstm2 alleviated oxidative stress damage of aging dermal fibroblasts by modulating mitochondrial oxidative phosphorylation, and promoted dermal fibroblasts to regulate skin epidermal cell function by paracrine secretion of Nascent Polypeptide-Associated Complex Alpha subunit (NACA). Furthermore, we confirmed that NACA is a novel skin epidermal cell protective molecule that regulates skin epidermal cell turnover through the ROS-ERK-ETS-Cyclin D pathway. Our findings demonstrate the feasibility and efficacy of EVs-mediated delivery of Gstm2 for aged skin treatment and unveil novel roles of GSTM2 and NACA for improving aging skin.

Effect of needle-free injection on psychological insulin resistance and insulin dosage in patients with type 2 diabetes.

Background and objective: Psychological insulin resistance (PIR), which refers to the reluctance of diabetic patients to use insulin, is a frequently encountered clinical issue. Needle-free injection (NFI) offers advantages in terms of expediting insulin absorption and mitigating adverse reactions related to injection. To evaluate the effects of subcutaneous injection of insulin aspart 30 with NFI on PIR and insulin dosage in patients with type 2 diabetes mellitus (T2DM). Methods: Sixty-four patients with T2DM participated in this randomized, prospective, open, crossover study. Insulin aspart 30 was administered subcutaneously to each subject via QS-P NFI and Novo Pen 5 (NP) successively. The effects of NFI on PIR were analyzed. Differences in insulin dosage, glycemic variability, and injection safety were compared at similar levels of glycemic control. Results: After the administration of NFI, the insulin treatment attitude scale score decreased (53.7 ± 7.3 vs. 58.9 ± 10.7, p<0.001), the insulin treatment adherence questionnaire score increased (46.3 ± 4.9 vs. 43.8 ± 7.1, p<0.001), and the insulin treatment satisfaction questionnaire score increased (66.6 ± 10.5 vs. 62.4 ± 16.5, p<0.001). At the same blood glucose level, NFI required a smaller dosage of insulin aspart 30 compared with that of NP (30.42 ± 8.70 vs. 33.66 ± 9.13 U/d, p<0.001). There were no differences in glycemic variability indices (standard deviation, mean amplitude of glycemic excursion or coefficient of variation) between the two injection methods. Compared with NP, NFI did not increase the incidence of hypoglycemia (17.2% vs. 14.1%, p=0.774), and it decreased the incidence of induration (4.7% vs. 23.4%, p=0.002) and leakage (6.3% vs. 20.3%, p=0.022) while decreasing the pain visual analog scale score (2.30 ± 1.58 vs. 3.11 ± 1.40, p<0.001). Conclusion: NFI can improve PIR in patients with T2DM and be used with a smaller dose of insulin aspart 30 while maintaining the same hypoglycemic effect. Clinical trial registration: https://www.chictr.org.cn/, identifier ChiCTR2400083658.

Needle-Free Injection of Metformin Ameliorates Skin Photoaging Through Inhibition of Ferroptosis and Oxidative Stress.

BACKGROUND: Skin photoaging is a complex process of skin aging caused by continuous exposure to ultraviolet (UV) radiation through oxidative stress and other pathways, yet effective treatments are scarce. Metformin is a drug with both anti-senescence and antioxidant functions; however, there are fewer studies on photoaging. The study aimed to investigate the role of needle-free injection of metformin in alleviating ultraviolet radiation B (UVB) induced skin photoaging, and to explore the mechanisms through which metformin alleviates fibroblast photoaging by inhibiting ferroptosis and oxidative stress. METHODS: In our study, we initially performed bioinformatic analysis on the gene expression profile (GSE38308), and our RNA sequencing (RNA-Seq) found that photoaging is associated with ferroptosis. We investigated the potential skin-protective mechanism of metformin by utilizing a UVB-induced rat skin photoaging model and human skin fibroblasts (HSF) treated with UVB. For in vitro experiments, cellular senescence was detected using SA-ß-galactosidase staining and p16 in western blot. Ferroptosis and oxidative stress were assessed via western blot (glutathione Peroxidase 4 (GPX4) and nuclear factor erythroid-2-related factor 2 (Nrf2)), reactive oxygen species (ROS) levels, transmission electron microscope, Lillie's staining, and immunofluorescence staining. During in vivo experiments, metformin was administered by needle-free jet injectors injected into the backs of rats. The effectiveness of metformin was detected using the Masson staining and western blot. RESULTS: We found that the ferroptosis pathway was closely associated with photoaging through bioinformatics analysis. In the UVB-induced photoaging HSF cells, treatment with metformin exhibits the following effects: a reduction in blue-stained granules in SA-ß-galactosidase staining and a decrease in the expression of p16, indicating a reduction in cellular senescence. Moreover, metformin leads to decreased ROS levels and increased expression of the oxidative stress-related protein Nrf2, suggesting inhibition of oxidative stress within the cells. Additionally, metformin results in an elevation of GPX4 expression, a decrease in blue-stained granules in Lillie's staining, and a reduction in ferroptosis-associated mitochondrial damage, indicating a decline in ferroptosis. Needle-free injection of metformin could directly achieve therapeutic effects by affecting HSF cells in the dermis. The needle-free injection of metformin treatment effectively improved the photoaging skin in rats compared to the photoaging group, ameliorated oxidative stress, and reduced ferroptosis. CONCLUSIONS: Our data highlights a novel needle-free injection of metformin that improves photoaging and has good therapeutic potential.

Optothermal Needle-Free Injection of Vaterite Nanocapsules.

The propulsion and acceleration of nanoparticles with light have both fundamental and applied significance across many disciplines. Needle-free injection of biomedical nano cargoes into living tissues is among the examples. Here a new physical mechanism of laser-induced particle acceleration is explored, based on abnormal optothermal expansion of mesoporous vaterite cargoes. Vaterite nanoparticles, a metastable form of calcium carbonate, are placed on a substrate, underneath a target phantom, and accelerated toward it with the aid of a short femtosecond laser pulse. Light absorption followed by picosecond-scale thermal expansion is shown to elevate the particle's center of mass thus causing acceleration. It is shown that a 2 µm size vaterite particle, being illuminated with 0.5 W average power 100 fsec IR laser, is capable to overcome van der Waals attraction and acquire 15m sec-1 velocity. The demonstrated optothermal laser-driven needle-free injection into a phantom layer and Xenopus oocyte in vitro promotes the further development of light-responsive nanocapsules, which can be equipped with additional optical and biomedical functions for delivery, monitoring, and controllable biomedical dosage to name a few.

Research progress of needle-free injection technology / 药学学报

Needle-free injection technology (NFIT) refers to the drug delivery systems in which drugs are propelled as high-speed jet streams using any of the pressure source to penetrate the skin to the required depth. NFIT is a promising drug delivery system as it enables the injection of liquids, powders, and depot/projectiles, and has the advantages of preventing needle stick accidents, improving drug bioavailability, eliminating needle-phobia, increasing vaccine immunity, simplifying operations and is convenient for patients to use. NFIT and its research background, the structure and classification of needle-free jet injectors (NFJI), drugs that can be delivered using NFJI and the factors affecting the injection effect are comprehensively reviewed in this paper. The limitations and potential development directions are summarized to provide a theoretical basis for the application and development of NFIT.

Safety and Immunogenicity of an Andes Virus DNA Vaccine by Needle-Free Injection: A Randomized, Controlled Phase 1 Study.

BACKGROUND: Andes virus (ANDV), a rodent-borne hantavirus, causes hantavirus pulmonary syndrome (HPS). The safety and immunogenicity of a novel ANDV DNA vaccine was evaluated. METHODS: Phase 1, double-blind, dose-escalation trial randomly assigned 48 healthy adults to placebo or ANDV DNA vaccine delivered via needle-free jet injection. Cohorts 1 and 2 received 2 mg of DNA or placebo in a 3-dose (days 1, 29, 169) or 4-dose (days 1, 29, 57, 169) schedule, respectively. Cohorts 3 and 4 received 4 mg of DNA or placebo in the 3-dose and 4-dose schedule, respectively. Subjects were monitored for safety and neutralizing antibodies by pseudovirion neutralization assay (PsVNA50) and plaque reduction neutralization test (PRNT50). RESULTS: While 98% and 65% of subjects had at least 1 local or systemic solicited adverse event (AE), respectively, most AEs were mild or moderate; no related serious AEs were detected. Cohorts 2, 3, and 4 had higher seroconversion rates than cohort 1 and seropositivity of at least 80% by day 197, sustained through day 337. PsVNA50 geometric mean titers were highest for cohort 4 on and after day 197. CONCLUSIONS: This first-in-human candidate HPS vaccine trial demonstrated that an ANDV DNA vaccine was safe and induced a robust, durable immune response. Clinical Trials Registration. NCT03682107.

High-Pressure Delivery of Oncolytic Viruses via Needle-Free Injection Preserves Therapeutic Activity.

Intratumoural delivery of oncolytic viruses (OVs) to solid tumours is currently performed via multiple percutaneous methods of needle injections (NI). In this study, we investigated the potential use of a novel delivery approach, needle-free injection (NFI), to administer OVs to subcutaneous tumours. The stability and genetic integrity of several RNA and DNA viruses exposed to high-pressure jet injectors were first evaluated in vitro. We demonstrate that replication competence and infectivity of the viruses remained unchanged after NFI, as compared to traditional NI. Using the oncolytic Vesicular Stomatitis Virus expressing luciferase (VSVΔ51-Luc) in the syngeneic CT26 subcutaneous tumour model, we show that NFI administration not only successfully delivers infectious particles but also increases the dissemination of the virus within the tumour tissues when compared to NI. Furthermore, mice treated with VSVΔ51-Luc by NFI delivery showed similar reduction in tumour growth and survival compared to those with needle-administered virus. These results indicate that NFI represents a novel approach to administer and potentially increase the spread of OVs within accessible solid tumours, highlighting its usefulness in virotherapy.

Needle-free electronically controlled jet injection with corticosteroids in recalcitrant keloid scars: a retrospective study and patient survey.

First-line treatment of keloids consists of intralesional needle injections with corticosteroids, but generally entails multiple painful sessions, resulting in variable clinical outcomes. Novel needle-free jet injectors may facilitate more effective and patient-friendly dermal drug delivery. Here, we evaluated the effectiveness, tolerability and patient satisfaction of intralesional triamcinolone-acetonide (TCA) treatment in recalcitrant keloids using an electronically controlled pneumatic injector (EPI). A retrospective study was conducted in recalcitrant keloid patients with a history of severe pain during needle injections who received three sessions of EPI + TCA. Outcome measures included Patient and Observer Scar Assessment Scale (POSAS), Global Aesthetic Improvement Scale (GAIS), treatment-related pain (NRS), adverse effects, and patient satisfaction (survey). Ten patients with in total 283 keloids were included. The POSAS score significantly improved at follow-up and GAIS was reported as '(very) improved' for all patients. EPI + TCA was well-tolerated with a significantly lower NRS pain score compared to needle + TCA (pilot treatment). Only minor adverse effects occurred, and 90% of patients preferred EPI over needle treatment. EPI + TCA is an effective and tolerable treatment for patients with recalcitrant keloids. The minimal treatment-related pain and high patient satisfaction makes it a promising treatment for patients with needle-phobia and/or severe pain during needle injections.

Immune Response of Inactivated Rabies Vaccine Inoculated via Intraperitoneal, Intramuscular, Subcutaneous and Needle-Free Injection Technology-Based Intradermal Routes in Mice.

Inoculation routes may significantly affect vaccine performance due to the local microenvironment, antigen localization and presentation, and, therefore, final immune responses. In this study, we conducted a head-to-head comparison of immune response and safety of inactivated rabies vaccine inoculated via intraperitoneal (IP), intramuscular (IM), subcutaneous (SC) and needle-free injection technology-based intradermal (ID) routes in ICR mice. Immune response was assessed in terms of antigen-specific antibodies, antibody subtypes and neutralizing antibodies for up to 28 weeks. A live rabies virus challenge was also carried out to evaluate vaccine potency. The dynamics of inflammatory cell infiltration at the skin and muscle levels were determined via histopathological examination. The kinetics and distribution of a model antigen were also determined by using in vivo fluorescence imaging. Evidence is presented that the vaccine inoculated via the ID route resulted in the highest antigen-specific antibody and neutralizing antibody titers among all administration routes, while IP and IM routes were comparable, followed by the SC route. Antibody subtype analysis shows that the IP route elicited a Th1-biased immune response, while SC and IM administration elicited a prominent Th2-type immune response. Unexpectedly, the ID route leads to a balanced Th1 and Th2 immune response. In addition, the ID route conferred effective protection against lethal challenge with 40 LD50 of the rabies CVS strain, which was followed by IP and IM routes. Moreover, a one-third dose of the vaccine inoculated via the ID route provided comparable or higher efficacy to a full dose of the vaccine via the other three routes. The superior performance of ID inoculation over other routes is related to longer local retention at injection sites and higher lymphatic drainage. Histopathology examination reveals a transient inflammatory cell infiltration at ID and IM injection sites which peaked at 48 h and 24 h, respectively, after immunization, with all side effects disappearing within one week. These results suggest that needle-free injection technology-based ID inoculation is a promising strategy for rabies vaccination in regard to safety and efficacy.

Experimental investigation of the optimal driving pressure for a larger-volume controllable jet injection system.

Jet injection technology has become the alternative drug delivery method of conventional needle-based injection due to its obvious advantages. In order to meet the demand for larger volume injection, the pneumatic jet injection systems have efficiently administrated vaccine up to 1 mL in human. Our recent study has also demonstrated that controlling the driving pressure enabled the pneumatic jet injection system to deliver larger volumes of drugs to target sites at desired rates and times. This work continues to explore the optimal two-phase driving pressure combination with better injection efficiency for typical larger-volume (1.0 mL) jet injection with controllable pneumatic jet injection system. Under the combination of a first phase driving pressure of 1.00 MPa and a second phase driving pressure ranging from 0.25 to 0.90 MPa, dynamic characteristics, dispersion characteristics and pharmacokinetic characteristics of this controllable jet injection system were quantitatively analyzed. In all experiments, it was confirmed that the optimal driving pressure combination of 1.0 mL ejection volume was close to (1.00-0.50) MPa. That is, the injection velocities of 151.85 m/s and 102.01 m/s for the first and second phase respectively facilitated better injection performance with a controlled release of 1.0 mL ejection volume. This strategy is practical for facilitating the clinical application of large-volume controllable jet injection systems.

A self-controlled, cross-over study of intensive insulin treatment with needle-based injection versus needle-free injection in hospitalized patients with type 2 diabetes.

Background and Aims: Needle injection and needle-free injection were proven effective in improving glycated hemoglobin (HbA1c) in type 2 diabetes mellitus (T2DM) patients. However, it is unclear if needle-free and needle injections of insulin during intensive insulin therapy in hospitalized patients provide similar efficacy and safety benefits. Methods: A self-controlled cross-over study was conducted on 62 patients with T2DM who received intensive long-acting and short-acting insulin injections with or without needles. The 7-point blood glucose test was performed on the 6th day after insulin administration and the injection method switched on the 7th day of hospitalization. The difference was compared in 7-point blood glucose levels. Results: The blood glucose levels at fasting (mean difference=-1.09 ± 2.38mmol/L, 95% CI, -1.69 to -0.48, p=0.0007) and post-breakfast (-1.14 ± 3.02mmol/L, 95%CI, -1.91 to -0.37, p=0.004) were better when patients were receiving needle-free injections compared to when receiving a needle injection. Indeed, daily blood glucose fluctuation, which presented as the area under the curve of glycemia, was decreased in needle-free injection periods (-0.3.48 ± 9.64, 95%CI, -5.95 to -1.01, p=0.0065). There was no significant difference in the dose of long-acting insulin between the two injection methods (-0.32 ± 2.69, 95%CI, -0.99 to 0.37, p>0.05). The dose of fast-acting insulin during the needle-free period was lower than that of when patients received needle injections (-1.66 ± 6.45, 95%CI, -3.29 to -0.025, p<0.05). There was no significant difference in satisfaction between the two regimens (-0.59 ± 1.55,95%CI, -0.938 to 0.509, p=0.557), but there was a significant difference in pain experience, favoring needle-free injections (p < 0.001). Conclusion: Glycemia was better controlled by needle-free insulin injections in hospitalized T2DM patients subjected to intensive glycemic control. These patients also experienced less pain than when insulin was injected with a needle.

Spring-Powered Needle-Free Injection of Triamcinolone Acetonide and 5-Fluorouracil for Keloid Treatment.

Introduction: Keloid is an abnormal fibroproliferative healing response characterized by excessive and invasive tissue growth beyond the wound boundaries. The conventional treatment involves injecting drugs such as triamcinolone acetonide (TA), 5-fluorouracil (5-FU), or their combination intralesionally. However, the pain associated with injections often leads to low patient compliance and treatment failure. The spring-powered needle-free injector (NFI) provides an affordable alternative option for drug delivery with reduced pain. Case: This case report presents a 69-year-old female patient with a keloid treated using a spring-powered needle-free injector (NFI) for drug delivery. The keloid was assessed using the Vancouver Scar Scale (VSS) and the Patient and Observer Scar Assessment Scale (POSAS). The patient's pain level was measured using the Numeric Pain Rating Scale (NPRS). TA and 5-FU mixed with lidocaine were loaded into the NFI and injected at a dose of 0.1 mL/cm2. The treatment was repeated twice a week. After four sessions, the keloid flattened by 0.5 cm, VSS score decreased from 11 to 10, and POSAS scores decreased from 49 to 43 (observer) and from 50 to 37 (patient). The NPRS during each procedure was 1, indicating minimal pain. Discussion: The spring-powered NFI is a simple and cost-effective device that operates based on Hooke's law, producing a high-pressure fluid jet for effective skin penetration. The NFI demonstrated effectiveness in treating keloid lesions, resulting in visible improvement after four treatments. Conclusion: The spring-powered NFI offers an affordable and painless alternative to keloid treatment.

Bubble dynamics and speed of jets for needle-free injections produced by thermocavitation.

Significance: The number of injections administered has increased dramatically worldwide due to vaccination campaigns following the COVID-19 pandemic, creating a problem of disposing of syringes and needles. Accidental needle sticks occur among medical and cleaning staff, exposing them to highly contagious diseases, such as hepatitis and human immunodeficiency virus. In addition, needle phobia may prevent adequate treatment. To overcome these problems, we propose a needle-free injector based on thermocavitation. Aim: Experimentally study the dynamics of vapor bubbles produced by thermocavitation inside a fully buried 3D fused silica chamber and the resulting high-speed jets emerging through a small nozzle made at the top of it. The injected volume can range from ∼0.1 to 2 µL per shot. We also demonstrate that these jets have the ability to penetrate agar skin phantoms and ex-vivo porcine skin. Approach: Through the use of a high-speed camera, the dynamics of liquid jets ejected from a microfluidic device were studied. Thermocavitation bubbles are generated by a continuous wave laser (1064 nm). The 3D chamber was fabricated by ultra-short pulse laser-assisted chemical etching. Penetration tests are conducted using agar gels (1%, 1.25%, 1.5%, 1.75%, and 2% concentrations) and porcine tissue as a model for human skin. Result: High-speed camera video analysis showed that the average maximum bubble wall speed is about 10 to 25 m/s for almost any combination of pump laser parameters; however, a clever design of the chamber and nozzle enables one to obtain jets with an average speed of ∼70 m/s. The expelled volume per shot (0.1 to 2 µl) can be controlled by the pump laser intensity. Our injector can deliver up to 20 shots before chamber refill. Penetration of jets into agar of different concentrations and ex-vivo porcine skin is demonstrated. Conclusions: The needle-free injectors based on thermocavitation may hold promise for commercial development, due to their cost and compactness.

Efficacy and safety of needle-free jet injector-assisted intralesional treatments in dermatology-a systematic review.

Needle-free jet injectors are used for the intralesional treatment of various dermatological indications. However, a systematic review that evaluates the efficacy and safety of these treatments has not been published. The objectives of this study are to evaluate the efficacy and safety of needle-free jet injections for dermatological indications and to provide evidence-based treatment recommendations. An electronic literature search was conducted in April 2022. Two reviewers independently selected studies based on predefined criteria and performed a methodological quality assessment using the Cochrane Collaborations risk-of-bias 2.0 assessment tool and Newcastle-Ottawa Scale. Thirty-seven articles were included, involving 1911 participants. Dermatological indications included scars, alopecia areata, hyperhidrosis, nail diseases, non-melanoma skin cancer, common warts, local anesthesia, and aesthetic indications. Keloids and other types of scars (hypertrophic, atrophic, and burn scars) were investigated most frequently (n = 7). The included studies reported favorable efficacy and safety outcomes for intralesional jet injector-assisted treatment with triamcinolone acetonide/hexacetonide, 5-fluorouracil, bleomycin, or hyaluronic acid. Two high-quality studies showed good efficacy and tolerability of intralesional jet injections with a combination of 5-fluorouracil and triamcinolone acetonide in hypertrophic scars and with saline in boxcar and rolling acne scars. No serious adverse reactions and good tolerability were reported in the included studies. Overall, the methodological quality of the included studies was low. Limited evidence suggests that needle-free jet injector-assisted intralesional treatment is efficacious and safe for hypertrophic and atrophic acne scars. More well-powered RCTs investigating the efficacy and safety of jet injector treatment in dermatology are warranted to make further evidence-based recommendations.

Improved DNA Vaccine Delivery with Needle-Free Injection Systems.

DNA vaccines have inherent advantages compared to other vaccine types, including safety, rapid design and construction, ease and speed to manufacture, and thermostability. However, a major drawback of candidate DNA vaccines delivered by needle and syringe is the poor immunogenicity associated with inefficient cellular uptake of the DNA. This uptake is essential because the target vaccine antigen is produced within cells and then presented to the immune system. Multiple techniques have been employed to boost the immunogenicity and protective efficacy of DNA vaccines, including physical delivery methods, molecular and traditional adjuvants, and genetic sequence enhancements. Needle-free injection systems (NFIS) are an attractive alternative due to the induction of potent immunogenicity, enhanced protective efficacy, and elimination of needles. These advantages led to a milestone achievement in the field with the approval for Restricted Use in Emergency Situation of a DNA vaccine against COVID-19, delivered exclusively with NFIS. In this review, we discuss physical delivery methods for DNA vaccines with an emphasis on commercially available NFIS and their resulting safety, immunogenic effectiveness, and protective efficacy. As is discussed, prophylactic DNA vaccines delivered by NFIS tend to induce non-inferior immunogenicity to electroporation and enhanced responses compared to needle and syringe.

Needle-free injection system delivery of ZyCoV-D DNA vaccine demonstrated improved immunogenicity and protective efficacy in rhesus macaques against SARS-CoV-2.

The apprehension of needles related to injection site pain, risk of transmitting bloodborne pathogens, and effective mass immunization have led to the development of a needle-free injection system (NFIS). Here, we evaluated the efficacy of the NFIS and needle injection system (NIS) for the delivery and immunogenicity of DNA vaccine candidate ZyCoV-D in rhesus macaques against SARS-CoV-2 infection. Briefly, 20 rhesus macaques were divided into 5 groups (4 animals each), that is, I (1 mg dose by NIS), II (2 mg dose by NIS), III (1 mg dose by NFIS), IV (2 mg dose by NFIS) and V (phosphate-buffer saline [PBS]). The macaques were immunized with the vaccine candidates/PBS intradermally on Days 0, 28, and 56. Subsequently, the animals were challenged with live SARS-CoV-2 after 15 weeks of the first immunization. Blood, nasal swab, throat swab, and bronchoalveolar lavage fluid specimens were collected on 0, 1, 3, 5, and 7 days post infection from each animal to determine immune response and viral clearance. Among all the five groups, 2 mg dose by NFIS elicited significant titers of IgG and neutralizing antibody after immunization with enhancement in their titers postvirus challenge. Besides this, it also induced increased lymphocyte proliferation and cytokine response. The minimal viral load post-SARS-CoV-2 challenge and significant immune response in the immunized animals demonstrated the efficiency of NFIS in delivering 2 mg ZyCoV-D vaccine candidate.

Comparison of efficacy of needle-free injection versus injection by needle for iron supplementation of piglets: a double blind randomized controlled trial.

BACKGROUND: In pig husbandry, most piglets receive an intramuscular injection with iron around three days of age for the prevention of hypochromic, microcytic anaemia. In recent years an increased interest is noted for needle-free injections, because of efficiency and safety for man and animal. This study aims to support the evidence on efficacy to extent the registration of a commercial iron supplement with a needle-free administration application. To this aim the study has two objectives: 1) to determine the effect of needle-free injection of the iron supplement on the mean blood Haemoglobin level at weaning, as primary outcome, and mean Haematocrit and mean Body weight of pigs at weaning as secondary outcome compared to no treatment, as main determinant of iron deficiency anaemia in piglets at time of weaning; 2) to compare the effects of needle-free administration of the iron supplement with regular injection by needle, with regard to the course over time of Haemoglobin, Haematocrit, piglet growth and the differentiated haematological and serum iron parameters. METHODS: A double blind randomized controlled trial was conducted with 72 piglets, 8 piglets per litter from 9 litters. At three days of age pigs were selected, based on body weight, and random allocated to three study groups: a) control non-treated group (2 pigs per litter, 18 in total), b) a group with regular iron injection by needle injection (3 pigs per litter, 27 in total), c) a group that received iron by needle-free injection (3 pigs per litter, 27 in total). At four points in time (day 3, 14, 26 and 40) piglets were weighed and bled to analyse the dynamics of red blood counts and haematological parameters as well as serum iron parameters. The primary outcome parameter was the Haemoglobin (Hb) level on day 26. Of secondary importance were Haematocrit (Ht) and body weight (BW) at weaning and parameters with tertiary importance were the course of Hb, Ht and differentiated red blood cell parameters, serum iron, iron binding capacity and iron saturation. In the statistical analyses, linear mixed effect regression modelling was used to account for repeated measures within litters and pigs. RESULTS: The analyses showed that needle-free administration was as efficacious to prevent iron deficiency anaemia at day 26 as administration using regular needle injection, compared to the control group. The mean level of Hb and Ht of pigs in the needle and needle-free group did not differ significantly. No side effects were observed. CONCLUSION: It is concluded that needle-free iron administration of the tested product is as efficacious as regular administration by needle injection.

A highly efficient needle-free-injection delivery system for mRNA-LNP vaccination against SARS-CoV-2.

Despite the various vaccines that have been developed to combat the coronavirus disease 2019 (COVID-19) pandemic, the persistent and unpredictable mutations of the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) require innovative and unremitting solutions to cope with the resultant immune evasion and establish a sustainable immune barrier. Here we introduce a vaccine-delivery system with a combination of a needle-free injection (NFI) device and a SARS-CoV-2-Spike-specific mRNA-Lipid Nanoparticle (LNP) vaccine. The benefits are duller pain and a significant increase of immunogenicity compared to the canonical needle injection (NI). From physicochemical and bioactivity analyses, the structure of the mRNA-LNP maintains stability upon NFI, contradictory to the belief that LNPs are inclined towards destruction under the high-pressure conditions of NFI. Moreover, mRNA-LNP vaccine delivered by NFI induces significantly more binding and neutralizing antibodies against SARS-CoV-2 variants than the same vaccine delivered by NI. Heterogeneous vaccination of BA.5-LNP vaccine with NFI enhanced the generation of neutralizing antibodies against Omicron BA.5 variants in rabbits previously vaccinated with non-BA.5-specific mRNA-LNP or other COVID-19 vaccines. NFI parameters can be adjusted to deliver mRNA-LNP subcutaneously or intramuscularly. Taken together, our results suggest that NFI-based mRNA-LNP vaccination is an effective substitute for the traditional NI-based mRNA-LNP vaccination.

Effect of a needle-free system versus traditional anesthesia on pain perception during palatal injections in children.

BACKGROUND: Needle-free injection systems can contribute to the prevention of needle-related pain during palatal infiltration anesthesia (PIA) in children. Research on this topic in children is required. AIM: The purpose of this clinical study was to evaluate the effectiveness and patient preference of a needle-free system versus traditional anesthesia (TA) on pain perception during PIA in children. DESIGN: The study was designed as a randomized, controlled crossover clinical study with 48 children aged 6-12 years requiring dental treatment with PIA in bilateral maxillary primary molars. TA was applied on one side and the Comfort-in™ injection system (CIS) on the other side in two separate sessions. Then, patient preference was recorded. The pain perception during PIA was evaluated using the Wong-Baker FACES Pain Rating Scale (PRS) and the Face, Legs, Activity, Cry, Consolability (FLACC) Scale. The data were analyzed for statistical significance (p < .05). RESULTS: There were statistically significant differences between the TA and the CIS according to the PRS and FLACC Scale scores. On both scales, significantly higher pain ratings were observed in the TA group during PIA (p < .001). There was a statistically significant difference in terms of patient preference (p < .001). Although 77.1% (n = 37) of the children preferred the CIS, 22.9% (n = 11) preferred the TA. Moreover, patient preference for the CIS was significantly higher in older children (p < .01). CONCLUSIONS: The application of a needle-free system during PIA ensured a decrease in pain perception in children.