Background/Objectives: This study aimed to develop gel nanoemulsions (NEs) of Brazilian essential oils (EOs) from Eugenia uniflora and Psidium guajava, as well as to perform chemical characterization and investigate the antimicrobial activity of the EOs and NEs. Results/Conclusions: The main chemical compounds of E. uniflora EO were curzerene (34.80%) and germacrene B (11.92%), while those of P. guajava EO were β-caryophyllene (25.92%), β-selinene (22.64%), and γ-selinene (19.13%). The NEs of E. uniflora and P. guajava had droplet sizes of 105.30 and 99.50 nm and polydispersity index (PDI) values of 0.32 and 0.43, respectively. The NEs remained stable for 30 days of storage at 25 °C, with droplet sizes of 104.7 and 103.8 nm, PDI values below 0.50, and no phase separation. The NE of E. uniflora exhibited inhibition zones ranging from 8.41 to 15.13 mm against the Gram-positive bacterium Staphylococcus aureus and the Gram-negative bacteria Pseudomonas aeruginosa, Klebsiella pneumoniae, and Acinetobacter baumannii. Additionally, the NE of E. uniflora showed the largest inhibition zones against Candida albicans (20.97 mm) and Candida krusei (15.20 mm), along with low minimum inhibitory concentration (MIC) values (0.54–1.22 mg/mL) and minimal bactericidal concentration (MBC) values (4.84–11.02 mg/mL) against these pathogenic yeasts. The NE of P. guajava demonstrated low MIC (1.26 mg/mL) and MBC (11.35 mg/mL) values for C. krusei. The time–growth inhibition assay also suggests the effectiveness of the NE against the tested pathogens S. aureus and E. coli, highlighting its potential as a novel alternative therapeutic agent.

The use of innate products for the fast and efficient promotion of healing process has been one of the biomedical sector’s main bets for lesion treatment modernization process. The aim of this study was to develop and characterize bacterial cellulose-based (BC) wound dressings incorporated with green and red propolis extract (2 to 4%) and the active compounds p-coumaric acid and biochanin A (8 to 16 mg). The characterization of the nine developed samples (one control and eight active wound dressings) evidenced that the mechanics, physics, morphological, and barrier properties depended not only on the type of active principle incorporated onto the cellulosic matrix, but also on its concentration. Of note were the results found for transparency (28.59–110.62T₆₀₀ mm⁻¹), thickness (0.023–0.046 mm), swelling index (48.93–405.55%), water vapor permeability rate (7.86–38.11 g m² day⁻¹), elongation (99.13–262.39%), and antioxidant capacity (21.23–86.76 μg mL⁻¹). The wound dressing based on BC and red propolis was the only one that presented antimicrobial activity. The permeation and retention test revealed that the wound dressing containing propolis extract presented the most corneal stratum when compared with viable skin. Overall, the developed wound dressing showed potential to be used for treatment against different types of dermal lesions, according to its determined proprieties.

Alopecia areata is managed with oral corticosteroids, which has known side effects for patients. Given that a topical application of formulations containing a corticoid and a substance controlling hair loss progression could reduce or eliminate such adverse effects and increase the patient’s adherence to the treatment, this study prepares polymeric and lipidic nanoparticles (PNPs and NLCs) to co-entrap minoxidil and betamethasone and compares the follicular drug delivery provided by topical application of these nanoparticles. The prepared PNPs loaded 99.1 ± 13.0% minoxidil and 70.2 ± 12.8% betamethasone, while the NLCs entrapped 99.4 ± 0.1 minoxidil and 80.7 ± 0.1% betamethasone. PNPs and NLCs presented diameters in the same range, varying from 414 ± 10 nm to 567 ± 30 nm. The thermal analysis revealed that the production conditions favor the solubilization of the drugs in the nanoparticles, preserving their stability. In in vitro permeation studies with porcine skin, PNPs provided a 2.6-fold increase in minoxidil penetration into the follicular casts compared to the control and no remarkable difference in terms of betamethasone; in contrast, NLCs provided a significant (specifically, a tenfold) increase in minoxidil penetration into the hair follicles compared to the control, and they delivered higher concentrations of betamethasone in hair follicles than both PNPs and the control. Neither PNPs nor NLCs promoted transdermal permeation of the drugs to the receptor solution, which should favor a topical therapy. Furthermore, both nanoparticles targeted approximately 50% of minoxidil delivery to the follicular casts and NLCs targeted 74% of betamethasone delivery to the hair follicles. In conclusion, PNPs and NLCs are promising drug delivery systems for enhancing follicular targeting of drugs, but NLCs showed superior performance for lipophilic drugs.

Scarless skin regeneration is a challenge in regenerative medicine. Herein, we explore the regenerative potential of a Cupuaçu seed extract (Theobroma grandiflorum) to develop an innovative skin regeneration formulation based on chitosan-coated nanocapsules. Cupuaçu seed extract significantly stimulated cell proliferation and migration. A reparative gene expression profile could be verified following extract treatment, which included high levels of MKI67, a cellular proliferation marker, and extracellular matrix genes, such as ELN and HAS2, which code for elastin and hyaluronic acid synthase 2. Formulations with Cupuaçu seed extract successfully entrapped into nanocapsules (EE% > 94%) were developed. Uncoated or coated nanocapsules with low-molecular-weight chitosan presented unimodal size distribution with hydrodynamic diameters of 278.3 ± 5.0 nm (PDI = 0.18 ± 0.02) and 337.2 ± 2.1 nm (PDI = 0.27 ± 0.01), respectively. Both nanosystems were physically stable for at least 120 days and showed to be non-irritating to reconstructed human epidermis. Chitosan coating promoted active penetration into undamaged skin areas, which were still covered by the stratum corneum. In conclusion, the present study demonstrated for the first time the biotechnological potential of the frequently discarded Cupuaçu seed as a valuable pharmaceutical ingredient to be used in regenerative skin products.

Background/Objectives: Although androgenic alopecia is the most prevalent among non-cicatricial alopecia, it still lacks an effective and safe treatment. Dutasteride (DUT) shows promising results in hair regrowth; however, oral DUT intake causes serious sexual adverse events. Hence, we produced liposomes with different bilayer structures and evaluated the capability of such systems in increasing DUT accumulation in the hair follicles. Methods: In vitro skin penetration tests were performed with porcine ear skin, and the follicular targeting factor (Tf) was calculated as the ratio between DUT amount in HFs and DUT recovered from the sum of all skin layers. Results: While the stiffer DUT-loaded liposome was not able to target the hair follicles in 12 h (Tf = 0.15), a DUT-loaded liposome with an edge activator in its composition, i.e., transfersomes, promoted better control over DUT release and a higher Tf (0.32) (p < 0.005). Conclusions: Transfersomes present higher affinity with DUT providing a better controlled release; hence, they are a better option for DUT follicle targeting compared to liposomes. Further formulation optimizations are needed aiming to prolong such targeting effect.

Background/Objectives: Treatment options for androgenic alopecia are still very limited and lack long-term efficacy. Dutasteride (DUT) has gained interest as a potent inhibitor of 5α-reductase, allowing for spaced applications, but DUT oral intake can cause serious adverse effects. Herein, we developed, characterized, and assessed the potential of DUT-loaded ethosomes with increasing ethanolic concentrations for hair follicle (HF) targeting to treat androgenic alopecia, hypothesizing that ethanol’s interaction with HFs’ sebum might increase DUT targeting to the HFs. Methods: Ethosomes were obtained using the water-dropping method. After a hydrodynamic size screening, a 30% ethanol concentration was fixed. Ethosomes with 30% ethanol were also prepared and had their ethanolic content removed by rotary evaporation for the evaluation of ethanol in targeting DUT to the HFs. The targeting factor (Tf) was calculated as the ratio between the DUT amount in HFs and the total DUT amount recovered from all skin layers after in vitro porcine skin penetration tests for 12 and 24 h. Results: The ethanolic concentration affected the vesicles’ size and the targeting potential. While the dried ethosomes could not increase DUT accumulation in the HFs at both time points (Tf: 0.27 in 12 h and Tf: 0.28 in 24 h), the presence of 30% ethanol in the vesicles increased the Tf from 0.28 (12 h) to 0.34 (24 h), significantly superior (p < 0.05) than the dried ethosome and control (Tf: 0.24) in 24 h. Conclusion: Ethosomes with a 30% ethanolic concentration were slightly more efficient in targeting HFs for dutasteride delivery.