Effect of Allele-Specific Clcn7G213R siRNA Delivered Via a Novel Nanocarrier on Bone Phenotypes in ADO2 Mice on 129S Background.

Autosomal dominant osteopetrosis type 2 (ADO2) is a rare inherited bone disorder characterised by dense but brittle bones. It displays striking phenotypic variability, with the most severe symptoms, including blindness and bone marrow failure. Disease management largely relies on symptomatic treatment since there is no safe and effective treatment. Most ADO2 cases are caused by heterozygous loss-of-function mutations in the CLCN7 gene, which encodes an essential Cl-/H+ antiporter for proper bone resorption by osteoclasts. Thus, siRNA-mediated silencing of the mutant allele is a promising therapeutic approach, but targeting bone for first-in-human translation remains challenging. Here, we demonstrate the utility of silicon-stabilised hybrid lipid nanoparticles (sshLNPs) as a next-generation nucleic acid nanocarrier capable of delivering allele-specific siRNA to bone. Using a Clcn7G213R knock-in mouse model recapitulating one of the most common human ADO2 mutations and based on the 129S genetic background (which produces the most severe disease phenotype amongst current models), we show substantial knockdown of the mutant allele in femur when siRNA targeting the pathogenic variant is delivered by sshLNPs. We observed lower areal bone mineral density in femur and reduced trabecular thickness in femur and tibia, when siRNA-loaded sshLNPs were administered subcutaneously (representing the most relevant administration route for clinical adoption and patient adherence). Importantly, sshLNPs have improved stability over conventional LNPs and enable 'post hoc loading' for point-of-care formulation. The treatment was well tolerated, suggesting that sshLNP-enabled gene therapy might allow successful clinical translation of essential new treatments for ADO2 and potentially other rare genetic bone diseases.

A Study on the Use of the Phyto-Courier Technology in Tobacco Leaves Infected by Agrobacterium tumefaciens.

Climate change results in exceptional environmental conditions and drives the migration of pathogens to which local plants are not adapted. Biotic stress disrupts plants' metabolism, fitness, and performance, ultimately impacting their productivity. It is therefore necessary to develop strategies for improving plant resistance by promoting stress responsiveness and resilience in an environmentally friendly and sustainable way. The aim of this study was to investigate whether priming tobacco plants with a formulation containing silicon-stabilised hybrid lipid nanoparticles functionalised with quercetin (referred to as GS3 phyto-courier) can protect against biotic stress triggered by Agrobacterium tumefaciens leaf infiltration. Tobacco leaves were primed via infiltration or spraying with the GS3 phyto-courier, as well as with a buffer (B) and free quercetin (Q) solution serving as controls prior to the biotic stress. Leaves were then sampled four days after bacterial infiltration for gene expression analysis and microscopy. The investigated genes increased in expression after stress, both in leaves treated with the phyto-courier and control solutions. A trend towards lower values was observed in the presence of the GS3 phyto-courier for genes encoding chitinases and pathogenesis-related proteins. Agroinfiltrated leaves sprayed with GS3 confirmed the significant lower expression of the pathogenesis-related gene PR-1a and showed higher expression of peroxidase and serine threonine kinase. Microscopy revealed swelling of the chloroplasts in the parenchyma of stressed leaves treated with B; however, GS3 preserved the chloroplasts' mean area under stress. Furthermore, the UV spectrum of free Q solution and of quercetin freshly extracted from GS3 revealed a different spectral signature with higher values of maximum absorbance (Amax) of the flavonoid in the latter, suggesting that the silicon-stabilised hybrid lipid nanoparticles protect quercetin against oxidative degradation.

Novel hybrid silicon-lipid nanoparticles deliver a siRNA to cure autosomal dominant osteopetrosis in mice. Implications for gene therapy in humans.

Rare skeletal diseases are still in need of proper clinically available transfection agents as the major challenge for first-in-human translation relates to intrinsic difficulty in targeting bone without exacerbating any inherent toxicity due to used vector. SiSaf's silicon stabilized hybrid lipid nanoparticles (sshLNPs) constitute next-generation non-viral vectors able to retain the integrity and stability of constructs and to accommodate considerable payloads of biologicals, without requiring cold-chain storage. sshLNP was complexed with a small interfering RNA (siRNA) specifically designed against the human CLCN7G215R mRNA. When tested via single intraperitoneal injection in pre-puberal autosomal dominant osteopetrosis type 2 (ADO2) mice, carrying a heterozygous mutation of the Clcn7 gene (Clcn7G213R), sshLNP, this significantly downregulated the Clcn7G213R related mRNA levels in femurs at 48 h. Confirmatory results were observed at 2 weeks and 4 weeks after treatments (3 intraperitoneal injections/week), with rescue of the bone phenotype and demonstrating safety. The pre-clinical results will enable advanced preclinical development of RNA-based therapy for orphan and genetic skeletal disorders by safely and effectively delivering biologicals of interest to cure human systemic conditions.

The Effects of Salinity on the Anatomy and Gene Expression Patterns in Leaflets of Tomato cv. Micro-Tom.

Salinity is a form of abiotic stress that impacts growth and development in several economically relevant crops and is a top-ranking threat to agriculture, considering the average rise in the sea level caused by global warming. Tomato is moderately sensitive to salinity and shows adaptive mechanisms to this abiotic stressor. A case study on the dwarf tomato model Micro-Tom is here presented in which the response to salt stress (NaCl 200 mM) was investigated to shed light on the changes occurring at the expression level in genes involved in cell wall-related processes, phenylpropanoid pathway, stress response, volatiles' emission and secondary metabolites' production. In particular, the response was analyzed by sampling older/younger leaflets positioned at different stem heights (top and bottom of the stem) and locations along the rachis (terminal and lateral) with the goal of identifying the most responsive one(s). Tomato plants cv. Micro-Tom responded to increasing concentrations of NaCl (0-100-200-400 mM) by reducing the leaf biomass, stem diameter and height. Microscopy revealed stronger effects on leaves sampled at the bottom and the expression analysis identified clusters of genes expressed preferentially in older or younger leaflets. Stress-related genes displayed a stronger induction in lateral leaflets sampled at the bottom. In conclusion, in tomato cv. Micro-Tom subjected to salt stress, the bottom leaflets showed stronger stress signs and response, while top leaflets were less impacted by the abiotic stressor and had an increased expression of cell wall-related genes involved in expansion.

Phyto-Courier, a Silicon Particle-Based Nano-biostimulant: Evidence from Cannabis sativa Exposed to Salinity.

Global warming and sea level rise are serious threats to agriculture. The negative effects caused by severe salinity include discoloration and reduced surface of the leaves, as well as wilting due to an impaired uptake of water from the soil by roots. Nanotechnology is emerging as a valuable ally in agriculture: several studies have indeed already proven the role of silicon nanoparticles in ameliorating the conditions of plants subjected to (a) biotic stressors. Here, we introduce the concept of phyto-courier: hydrolyzable nanoparticles of porous silicon, stabilized with the nonreducing saccharide trehalose and containing different combinations of lipids and/or amino acids, were used as vehicle for the delivery of the bioactive compound quercetin to the leaves of salt-stressed hemp (Cannabis sativa L., Santhica 27). Hemp was used as a representative model of an economically important crop with multiple uses. Quercetin is an antioxidant known to scavenge reactive oxygen species in cells. Four different silicon-based formulations were administered via spraying in order to investigate their ability to improve the plant's stress response, thereby acting as nano-biostimulants. We show that two formulations proved to be effective at decreasing stress symptoms by modulating the amount of soluble sugars and the expression of genes that are markers of stress-response in hemp. The study proves the suitability of the phyto-courier technology for agricultural applications aimed at crop protection.

Topical siRNA delivery to the cornea and anterior eye by hybrid silicon-lipid nanoparticles.

The major unmet need and crucial challenge hampering the exciting potential of RNAi therapeutics in ophthalmology is to find an effective, safe and non-invasive means of delivering siRNA to the cornea. Although all tissues of the eye are accessible by injection, topical application is preferable for the frequent treatment regimen that would be necessary for siRNA-induced gene silencing. However, the ocular surface is one of the more complex biological barriers for drug delivery due to the combined effect of short contact time, tear dilution and poor corneal cell penetration. Using nanotechnology to overcome the challenges, we developed a unique silicon-based delivery platform for ocular delivery of siRNA. This biocompatible hybrid of porous silicon nanoparticles and lipids has demonstrated an ability to bind nucleic acid and deliver functional siRNA to corneal cells both in vitro and in vivo. Potent transfection of human corneal epithelial cells with siRNA-ProSilic® formulation was followed by a successful downregulation of reporter protein expression. Moreover, siRNA complexed with this silicon-based hybrid and applied in vivo topically to mice eyes penetrated across all cornea layers and resulted in a significant reduction of the targeted protein expression in corneal epithelium. In terms of siRNA loading capacity, system versatility, and potency of action, ProSilic provides unique attributes as a biodegradable delivery platform for therapeutic oligonucleotides.

Comparative Study of the Effects Exerted by N-Valproyl-L-Phenylalanine and N-valproyl-L-tryptophan on CA1 Hippocampal Epileptiform Activity in Rat.

BACKGROUND: The research on the improvement of epilepsy therapy is constantly growing. Valproyl-LPhenylalanine (VPA-Phen) and N-valproyl-L-tryptophan (VPA-Tryp) were synthesized to increase the antiepileptic efficacy of valproic acid. METHODS: VPA-Phen and VPA-Tryp were comparatively tested on CA1 hippocampal epileptiform bursting activity obtained by increasing potassium and lowering calcium and magnesium concentrations in the fluid perfusing rat brain slices. Each slice was treated with a single concentration (0.2, 0.5, 1 mM) of VPA-Phen or VPA-Tryp. Both burst duration and interburst frequency, during and after treatment, were off-line compared with baseline values. For both parameters, either the latency or the duration of drug-induced statistically significant responses was calculated, as well as the response magnitude. RESULTS: VPA-Phen significantly reduced both burst frequency and duration. Comparative analyses show that VPA-Phen and VPA-Tryp exert almost equivalent actions on both latency and magnitude of the observed inhibitory effects. The main observed difference between the two tested molecules concerned the duration of inhibitory effects, since VPA-Phen-dependent actions on both burst rate and duration were significantly shorter than the VPA-Tryp-induced ones. In addition, in some slices the above reported inhibitory responses were preceded by a "paradoxical" transient increase, more present at lower drug concentrations. CONCLUSIONS: Both VPA-Phen and VPA-Tryp exert significant inhibitory effects on hippocampal burst activity parameters. Although of comparable magnitude, VPA-Phen-dependent effects have a shorter duration than VPATryp- induced ones. Nevertheless, the present results confirm that the conjugation between VPA and aminoacids represents a valid tool to improve the efficacy of antiepileptic drugs and, as well as for VPA-Tryp, propose VPAPhen as a novel VPA derivative with enhanced pharmacological features.

Assessment of in vivo organ-uptake and in silico prediction of CYP mediated metabolism of DA-Phen, a new dopaminergic agent.

The drug development process strives to predict metabolic fate of a drug candidate, together with its uptake in major organs, whether they act as target, deposit or metabolism sites, to the aim of establish a relationship between the pharmacodynamics and the pharmacokinetics and highlight the potential toxicity of the drug candidate. The present study was aimed at evaluating the in vivo uptake of 2-Amino-N-[2-(3,4-dihydroxy-phenyl)-ethyl]-3-phenyl-propionamide (DA-Phen) - a new dopaminergic neurotransmission modulator, in target and non-target organs of animal subjects and integrating these data with SMARTCyp results, an in silico method that predicts the sites of cytochrome P450-mediated metabolism of drug-like molecules. Wistar rats, subjected to two different behavioural studies in which DA-Phen was intraperitoneally administrated at a dose equal to 0.03mmol/kg, were sacrificed after the experimental protocols and their major organs were analysed to quantify the drug uptake. The data obtained were integrated with in silico prediction of potential metabolites of DA-Phen using the SmartCYP predictive tool. DA-Phen reached quantitatively the Central Nervous System and the results showed that the amide bond of the DA-Phen is scarcely hydrolysed as it was found intact in analyzed organs. As a consequence, it is possible to assume that DA-Phen acts as dopaminergic modulator per se and not as a Dopamine prodrug, thus avoiding peripheral release and toxic side effects due to the endogenous neurotransmitter. Furthermore the identification of potential metabolites related to biotransformation of the drug candidate leads to a more careful evaluation of the appropriate route of administration for future intended therapeutic aims and potential translation into clinical studies.

In situ delivery of corticosteroids for treatment of oral diseases.

In many mucocutaneous disorders, corticosteroids therapy is currently central. Systemic therapy is restricted to severe disorders whereas topical applications are considered as the first-line treatment. The oral cavity environment, the medication form and other factors related to the delivery method are key factors for the therapy efficiency and effectiveness. Current marketed medications are not able to avoid wrong drug exposure and scarce patients' compliance. Innovative in situ delivery systems are able to prolong the drug retention time on the mucosa and to avoid the drawbacks of conventional formulations. This review is intended to give a general overview of oral mucocutaneous pathologies and highlight the potential of new technologies in designing innovative delivery systems able to release corticosteroids in situ for the treatment of various oral cavity disorders.

Development and Characterization of an Amorphous Solid Dispersion of Furosemide in the Form of a Sublingual Bioadhesive Film to Enhance Bioavailability.

Administered by an oral route, Furosemide (FUR), a diuretic used in several edematous states and hypertension, presents bioavailability problems, reported as a consequence of an erratic gastrointestinal absorption due to various existing polymorphic forms and low and pH-dependent solubility. A mucoadhesive sublingual fast-dissolving FUR based film has been developed and evaluated in order to optimize the bioavailability of FUR by increasing solubility and guaranteeing a good dissolution reproducibility. The Differential Scanning Calorimetry (DSC) analyses confirmed that the film prepared using the solvent casting method entrapped FUR in the amorphous state. As a solid dispersion, FUR increases its solubility up to 28.36 mg/mL. Drug content, thickness, and weight uniformity of film were also evaluated. The measured Young's Modulus, yield strength, and relative elongation of break percentage (EB%) allowed for the classification of the drug-loaded film as an elastomer. Mucoadhesive strength tests showed that the force to detach film from mucosa grew exponentially with increasing contact time up to 7667 N/m². FUR was quickly discharged from the film following a trend well fitted with the Weibull kinetic model. When applied on sublingual mucosa, the new formulation produced a massive drug flux in the systemic compartment. Overall, the proposed sublingual film enhances drug solubility and absorption, allowing for the prediction of a rapid onset of action and reproducible bioavailability in its clinical application.

Small endogenous molecules as moiety to improve targeting of CNS drugs.

INTRODUCTION: A major challenge in the development of novel neuro-therapeutic agents is to effectively overcome the blood-brain barrier (BBB), which acts as a 'working dynamic barrier'. The core problem in the treatment of neurodegenerative diseases is failed delivery of potential medicines due to their inadequate permeation rate. Areas covered: The present review gives a summary of endogenous moieties used in synthesizing prodrugs, derivatives and bioisosteric drugs appositely designed to structurally resemble physiological molecular entities able to be passively absorbed or carried by specific carrier proteins expressed at BBB level. In particular, this overview focuses on aminoacidic, glycosyl, purinergic, ureic and acidic fragments derivatives, most of which can take advantage from BBB carrier-mediated transporters, where passive diffusion is not permitted. Expert opinion: In the authors' perspective, further progress in this field could expedite successful translation of new chemical entities into clinical trials. Careful rationalization of the linkage between endogenous molecular structures and putative transporters binding sites could allow to useful work-flows and libraries for synthesizing new BBB-crossing therapeutic substances and/or multifunctional drugs for treatments of central disorders.

Design, synthesis and preliminary evaluation of dopamine-amino acid conjugates as potential D1 dopaminergic modulators.

The dopamine-amino acid conjugate DA-Phen was firstly designed to obtain a useful prodrug for the therapy of Parkinson's disease, but experimental evidence shows that it effectively interacts with D1 dopamine receptors (D1DRs), leading to an enhancement in cognitive flexibility and to the development of adaptive strategies in aversive mazes, together with a decrease in despair-like behavior. In this paper, homology modelling, molecular dynamics, and site mapping of D1 receptor were carried out with the aim of further performing docking studies on other dopamine conjugates compared with D1 agonists, in the attempt to identify new compounds with potential dopaminergic activity. Two new conjugates (DA-Trp 2C, and DA-Leu 3C) have been identified as the most promising candidates, and consequently synthesized. Preliminary evaluation in terms of distribution coefficient (DpH7.4), stability in rat brain homogenate, and in human plasma confirmed that DA-Trp (2C), and DA-Leu (3C) could be considered as very valuable candidates for further in vivo studies as new dopaminergic drugs.

Effects of DA-Phen, a dopamine-aminoacidic conjugate, on alcohol intake and forced abstinence.

The mesolimbic dopamine (DA) system plays a key role in drug reinforcement and is involved in the development of alcohol addiction. Manipulation of the DAergic system represents a promising strategy to control drug-seeking behavior. Previous studies on 2-amino-N-[2-(3,4-dihydroxy-phenyl)-ethyl]-3-phenyl-propionamide (DA-Phen) showed in vivo effects as a DA-ergic modulator. This study was aimed at investigate DA-Phen effects on operant behavior for alcohol seeking behavior, during reinstatement following subsequent periods of alcohol deprivation. For this purpose, male Wistar rats were tested in an operant paradigm of self-administration; behavioral reactivity and anxiety like-behavior during acute abstinence were evaluated. A characterization of DA-Phen CNS targeting by its quantification in the brain was also carried out. Our findings showed that DA-Phen administration was able to reduce relapse in alcohol drinking by 50% and reversed the alterations in behavioral reactivity and emotionality observed during acute abstinence. In conclusion, DA-Phen can reduce reinstatement of alcohol drinking in an operant-drinking paradigm following deprivation periods and reverse abstinence-induced behavioral phenotype. DA-Phen activity seems to be mediated by the modulation of the DAergic transmission. However further studies are needed to characterize DA-Phen pharmacodynamic and pharmacokinetic properties, and its potential therapeutic profile in alcohol addiction.

Studies on a new potential dopaminergic agent: in vitro BBB permeability, in vivo behavioural effects and molecular docking evaluation.

2-Amino-N-[2-(3,4-dihydroxy-phenyl)-ethyl]-3-phenyl-propionamide (DA-PHEN) has been previously synthesized to obtain a potential prodrug capable of release dopamine (DA) into CNS. However, DA-PHEN could act per se as a dopaminergic drug. In this study, the permeability transport (Pe), obtained by parallel artificial permeability assay (PAMPA), indicated a low passive transcellular transport (Pe = 0.32 ± 0.01 × 10(-6 )cm/s). Using the Caco-2 cell system, the Papp AP-BL in absorptive direction (3.36 ± 0.02 × 10(-5 )cm/s) was significantly higher than the Papp BL-AP in secretive direction (1.75 ± 0.07 × 10(-5 )cm/s), suggesting a polarized transport. The efflux ratio (Papp AP-BL/Papp BL-AP = 0.52 ± 0.02) indicated a low affinity of DA-PHEN to efflux carriers. The forced swim test highlighted a reduction of immobility time in both pre-test and test sessions (p < 0.0001), with an exacerbation in the number of headshakes and divings in the pretest (p < 0.0001). Morris water maze strengthened the hypothesis that DA-PHEN induces adaptive responses to environmental challenges which are involved on cognitive functions (DA-PHEN versus CTR: escape latency; p < 0.001; distance swum p < 0.001, time spent on target quadrant p < 0.001), without any change in locomotor activity for the administered dose. The molecular docking revealed the interaction of DA-PHEN with the identified D1 site mapping human brain receptor.

Acetaldehyde self-administration by a two-bottle choice paradigm: consequences on emotional reactivity, spatial learning, and memory.

Acetaldehyde, the first alcohol metabolite, is responsible for many pharmacological effects that are not clearly distinguishable from those exerted by its parent compound. It alters motor performance, induces reinforced learning and motivated behavior, and produces different reactions according to the route of administration and the relative accumulation in the brain or in the periphery. The effective activity of oral acetaldehyde represents an unresolved field of inquiry that deserves further investigation. Thus, this study explores the acquisition and maintenance of acetaldehyde drinking behavior in adult male rats, employing a two-bottle choice paradigm for water and acetaldehyde solution (from 0.9% to 3.2% v/v), over 8 weeks. The behavioral consequences exerted by chronic acetaldehyde intake are assessed by a set of different tests: trials in an open-field arena and elevated-plus maze provided information on both general motor and explorative activity, and anxiety-driven behavioral responses. The Morris water maze allowed the exploration of cognitive processes such as spatial learning and memory. Determination of acetaldehyde levels in the brain was carried out at the end of the drinking paradigm. Our results indicate that rats exposed for the first time to acetaldehyde at 0.9% displayed a regular and stable daily drinking pattern that reached higher values and a "peaks and drops" shaped-trend when acetaldehyde concentration was increased to 3.2%. Accordingly, an increase in acetaldehyde levels in the brain was determined compared to non-acetaldehyde drinking rats. Acetaldehyde intake during the free-choice paradigm exerted an anxiogenic response in the open-field arena and elevated-plus maze, which in turn correlates with an enhancement in cognitive flexibility and spatial orientation skills, when an adaptive response to a stressful environmental challenge was required. These findings further support the idea that acetaldehyde is indeed a centrally active and behaviorally relevant metabolite of alcohol.

Aloin delivery on buccal mucosa: ex vivo studies and design of a new locoregional dosing system.

CONTEXT: Chemoprevention of potential malignant disorders or cancerous lesions that affect oral mucosae requires extended duration of treatment. Locoregional delivery of natural products could represent a promising strategy for this purpose. OBJECTIVE: To investigate the aptitude of aloin to permeate through, or accumulate in, the buccal mucosa and to develop a new prolonged oro-mucosal drug delivery system. MATERIALS AND METHODS: Permeation/accumulation of aloin from Curacao Aloe (containing 50% barbaloin) was evaluated ex vivo, using porcine buccal mucosa as the most useful model to simulate human epithelium. Oro-mucosal matrix tablets were prepared by dispersing aloin (10% w/w) in Eudragit® RS 100 as, biocompatible, low permeable, pH-independent, and non-swelling polymer. The prepared tablets were evaluated for drug-polymer compatibility, weight variation, drug uniformity content, diameter, thickness, hardness, friability, swelling, mucoadhesive strength, and drug release. RESULTS: Aloin has low tendency to cross buccal mucosa, permeation is marginal, and high drug amounts remain entrapped into the epithelium. Matrix tablets characteristics were in agreement with pharmacopoeial requirements. Drug release showed highly reproducible Higuchian profile. Delivery through matrix tablets promoted drug accumulation in the mucosal tissue. DISCUSSION AND CONCLUSION: Following application of matrix tablets on porcine buccal mucosa, the amount of discharged drug recovered in the tissue should be sufficient to produce the desired effects, providing therapeutic drug levels directly at the site of action. Aloin-loaded tablets are valid candidates for prevention/treatment of potentially malignant disorders and oral cancer and could potentially lead to clinically relevant drug delivery system as coadjuvant of conventional chemotherapy/radiation therapy.

N-valproyl-L-phenylalanine as new potential antiepileptic drug: synthesis, characterization and in vitro studies on stability, toxicity and anticonvulsant efficacy.

Valproic acid (VPA) is considered first-line drug in treatment of generalized idiopathic seizures such as absence, generalized tonic-clonic and myoclonic seizures. Among major antiepileptic drugs, VPA is also considered effective in childhood epilepsies and infantile spasms. Due to its broad activity, VPA acts as a mood stabilizer in bipolar disorder and it is useful in migraine prophylaxis. Despite its long-standing usage, severe reactions to VPA, such as liver toxicity and teratogenicity, are reported. To circumvent side effects due to structural characteristics of VPA, we synthesized in good yield a new VPA-aminoacid conjugate, the N-valproyl-L-Phenylalanine, and characterized by FT-IR, MS, (13)C and (1)H- NMR analyses. The Log D(pH7.4) value (0.19) indicated that new molecule was potentially able to cross biological membranes. The resistance to chemical and enzymatic hydrolysis of N-valproyl-L-phenylalanine was also assessed. All trials suggested that the compound, at the pH conditions of the entire gastro-intestinal tract, remained unmodified. Furthermore, the new compound did not undergo enzymatic cleavage both in plasma and in cerebral medium up to 24 h. The toxicity assay on primary cultures of astrocytes indicated that the synthetized conjugate was less toxic than both free VPA and L-Phenylalanine. In this paper, the anticonvulsant activity of the new compound against epileptic burst discharges evoked in vitro in rat hippocampal slices was also evaluated. These preliminary results underline that N-valproyl-L-phenylalanine as new potential antiepileptic agent could represent a good candidate to further investigations.

Physical methods to promote drug delivery on mucosal tissues of the oral cavity.

INTRODUCTION: The success of drug delivery through the mucosal tissue of the oral cavity represents a current challenge as well as a great future perspective. The need for more rapid onset of action and improved absorption of medications has resulted in great development of drug delivery technologies that use physical methods to overcome the barrier properties of oral mucosae. AREAS COVERED: This review discusses the various physical techniques which have been, and are being, explored to sustain drug delivery in the oral cavity. In particular, supersaturation, eutectic formation, iontophoresis, electroporation, sonophoresis, laser radiation, photomechanical waves and needleless injection are considered. Following a careful selection of the most appropriate site and technique, in agreement with local variations of the oral mucosal permeability features, physical methods to promote drug delivery can improve treatment of diseases. EXPERT OPINION: Although physical methods are very promising to promote drug delivery through keratinized epithelial tissues, they are not extensively used on the oral cavity mucosae. The authors feel that, in the near future, these methods could be further developed to provide noninvasive and convenient means for locoregional/systemic delivery of drugs with poor bioavailability profile, short half-life and multiple doses scheduling. This review will help the readers in the selection of a suitable physical method for improving drug delivery in the oral cavity for future chances. The authors imagine that new formulations or devices will be marketed in the coming years.