Multiomic Profiling and Neuroprotective Bioactivity of Salvia Hairy Root-Derived Extracellular Vesicles in a Cellular Model of Parkinson's Disease.

Purpose: Extracellular vesicles (EVs) are promising tools for nanomedicine and nanobiotechnology. The purification of mammalian-derived EVs involves intensive processes, and their therapeutic application raises multiple safety and regulatory issues. Plants have the potential to serve as nonconventional sources of therapeutically relevant EVs. In this context, we recently identified hairy roots (HRs) of medicinal plants as a novel biotechnological platform to produce EVs for human health. Methods: Herein, we report the purification, omics profiling, and bioactivity of EVs isolated from HRs of the medicinal plants S. sclarea and S. dominica. EVs were isolated from conditioned media of HR cultures using differential ultracentrifugation (dUC) and size exclusion chromatography (SEC). The isolated EVs were characterized by nanoparticle tracking analysis (NTA) and electron microscopy. The proteomic and metabolomic profiles of the EVs were determined using mass spectrometry. Uptake studies and bioactivity assays, including confocal microscopy, MTT, flow cytometry, ROS quantification, and untargeted metabolomics analyses, were conducted in SH-SY5Y cells treated with the neurotoxin 6-hydroxydopamine (6-OHDA) to evaluate the therapeutic potential of EVs in an in vitro model of Parkinson's disease. Results: S. sclarea HRs released nanosized round-shaped EVs with a distinctive molecular signature. HR EVs from S. sclarea and S. dominica revealed conserved cargo of secondary metabolites, predominantly triterpenoids, which are known for their antioxidant properties. We showed that HR EVs are safe, enter the cells, and strongly inhibit apoptosis in a cellular model of Parkinson's disease. Cellular metabolomics revealed that EVs preserved metabolic homeostasis and mitigated cellular oxidative stress when co-administered with 6-OHDA. Mechanistically, HR EVs inhibited 6-OHDA autoxidation and substantially reduced the accumulation of its oxidative products, which are responsible for 6-OHDA-induced toxicity. Conclusion: Collectively, our findings provide compelling evidence that EVs isolated from the hairy roots of Salvia species are promising, non-mammalian alternative for the design of novel therapies targeting neurological disorders.

A Spironolactone-Based Prototype of an Innovative Biomedical Patch for Wound Dressing Applications.

The electrospinning process is an effective technique for creating micro- and nanofibers from synthetic and natural polymers, with significant potential for biomedical applications and drug delivery systems due to their high drug-loading capacity, large surface area, and tunable release times. Poly(L-lactic acid) (PLLA) stands out for its excellent thermo-mechanical properties, biodegradability, and bioabsorbability. Electrospun PLLA nanofibrous structures have been extensively investigated as wound dressings, sutures, drug delivery carriers, and tissue engineering scaffolds. This study aims to create and characterize electrospun PLLA membranes loaded with spironolactone (SP), mimicking active compounds of Ganoderma lucidum (GL), to develop a biodegradable patch for topical wound-healing applications. GL, a medicinal mushroom, enhances dermal wound healing with its bioactive compounds, such as polysaccharides and ganoderic acids. Focusing on GL extracts-obtained through green extraction methods-and innovative drug delivery, we created new fibers for wound-healing potential applications. To integrate complex mixtures of bioactive compounds into the fibers, we developed a prototype using a single pure substance representing the extract mixture. This painstaking work presents the results of the fabricating, wetting, moisture properties, material resilience, and full characterization of the product, providing a robust rationale for the fabrication of fibers imbued with more complex extracts.

Production and simulated digestion of high-load beads containing Schizochytrium oil encapsulated utilizing prilling technique.

The oil from the heterotroph Schizochytrium is a rich source of n-3 PUFA, particularly DHA, and therefore highly susceptible to oxidation. The present work reports the first application of coaxial prilling for the protection of this oil through microencapsulation. After process optimization, core-shell microparticles were produced with calcium or zinc alginate at different concentrations. Encapsulates were analyzed in their tocopherol and PUFA content. Prilling lowered the earlier but had little effect on the latter. Microcapsules coated with calcium alginate (1 % and 1.75 %) had higher oil load and encapsulation efficiency and were therefore submitted to in vitro digestion together with a simulated meal. Digesta were also analyzed with HPLC-qTOF and 1H NMR and compared to undigested encapsulates. While 1 % calcium shell granted lower oil release and protection from oxidation in the simulated gastrointestinal tract, chromatographic and spectroscopic data of digesta showed higher presence of lipid digestion products.

Hyaluronate loaded advanced wound dressing in form of in situ forming hydrogel powders: Formulation, characterization, and therapeutic potential.

In this paper, a blend composed of alginate-pectin-chitosan loaded with sodium hyaluronate in the form of an in situ forming dressing was successfully developed for wound repair applications. This complex polymeric blend has been efficiently used to encapsulate hyaluronate, forming an adhesive, flexible, and non-occlusive hydrogel able to uptake to 15 times its weight in wound fluid, and being removed without trauma from the wound site. Calorimetric and FT-IR studies confirmed chemical interactions between hyaluronate and polysaccharides blend, primarily related to the formation of a polyelectrolytic complex between hyaluronate and chitosan. In vivo wound healing assays on murine models highlighted the ability of the loaded hydrogels to significantly accelerate wound healing compared to a hyaluronic-loaded ointment. This was evident through complete wound closure in <10 days, accompanied by fully restored epidermal functionality and no indications of the site of excision or treatment. Therefore, all these results suggest that hyaluronate-loaded powders could be a very promising conformable dressing in several wound healing applications where exudate is present.

An Integrated Multilevel Approach Unveils Complex Seed-Nanoparticle Interactions and Their Implications for Seed Priming.

Nanotechnology has the potential to revolutionize agriculture with the introduction of engineered nanomaterials. However, their use is hindered by high cost, marginal knowledge of their interactions with plants, and unpredictable effects related to massive use in crop cultivation. Nanopriming is an innovative seed priming technology able to match economic, agronomic, and environmental needs in agriculture. The present study was focused on unveiling, by a multilevel integrated approach, undisclosed aspects of seed priming mediated by iron oxide magnetic nanoparticles in pepper seeds (Capsicum annuum), one of the most economically important crops worldwide. Inductively coupled plasma atomic emission mass spectrometry and scanning electron microscopy were used to quantify the MNP uptake and assess seed surface changes. Magnetic resonance imaging mapped the distribution of MNPs prevalently in the seed coat. The application of MNPs significantly enhanced the root and vegetative growth of pepper plants, whereas seed priming with equivalent Fe concentrations supplied as FeCl3 did not yield these positive effects. Finally, global gene expression by RNA-sequencing identified more than 2,200 differentially expressed genes, most of them involved in plant developmental processes and defense mechanisms. Collectively, these data provide evidence on the link between structural seed changes and an extensive transcriptional reprogramming, which boosts the plant growth and primes the embryo to cope with environmental challenges that might occur during the subsequent developmental and growth stages.

Hollow Particles Obtained by Prilling and Supercritical Drying as a Potential Conformable Dressing for Chronic Wounds.

The production of aerogels for different applications has been widely known, but the use of polysaccharide-based aerogels for pharmaceutical applications, specifically as drug carriers for wound healing, is being recently explored. The main focus of this work is the production and characterization of drug-loaded aerogel capsules through prilling in tandem with supercritical extraction. In particular, drug-loaded particles were produced by a recently developed inverse gelation method through prilling in a coaxial configuration. Particles were loaded with ketoprofen lysinate, which was used as a model drug. The core-shell particles manufactured by prilling were subjected to a supercritical drying process with CO2 that led to capsules formed by a wide hollow cavity and a tunable thin aerogel layer (40 µm) made of alginate, which presented good textural properties in terms of porosity (89.9% and 95.3%) and a surface area up to 417.0 m2/g. Such properties allowed the hollow aerogel particles to absorb a high amount of wound fluid moving very quickly (less than 30 s) into a conformable hydrogel in the wound cavity, prolonging drug release (till 72 h) due to the in situ formed hydrogel that acted as a barrier to drug diffusion.

Flogomicina: A Natural Antioxidant Mixture as an Alternative Strategy to Reduce Biofilm Formation.

The National Institute of Health has reported that approximately 80% of chronic infections are associated with biofilms, which are indicated as one of the main reasons for bacteria's resistance to antimicrobial agents. Several studies have revealed the role of N-acetylcysteine (NAC), in reducing biofilm formation induced by different microorganisms. A novel mixture made up of NAC and different natural ingredients (bromelain, ascorbic acid, Ribes nigrum, resveratrol, and pelargonium) has been developed in order to obtain a pool of antioxidants as an alternative strategy for biofilm reduction. The study has demonstrated that the mixture is able to significantly enhance NAC activity against different Gram-positive and Gram-negative bacteria. It has shown an increase in NAC permeation in vitro through an artificial fluid, moving from 2.5 to 8 µg/cm2 after 30 min and from 4.4 to 21.6 µg/cm2 after 180 min, and exhibiting a strongly fibrinolytic activity compared to the single components of the mixture. Moreover, this novel mixture has exhibited an antibiofilm activity against S aureus and the ability to reduce S. aureus growth by more than 20% in a time-killing assay, while on E. coli, and P. mirabilis, the growth was reduced by more than 80% compared to NAC. The flogomicina mixture has also been proven capable of reducing bacterial adhesion to abiotic surfaces of E.coli, by more than 11% concerning only the NAC. In combination with amoxicillin, it has been shown to significantly increase the drug's effectiveness after 14 days, offering a safe and natural way to reduce the daily dosage of antibiotics in prolonged therapies and consequently, reduce antibiotic resistance.

Alginate-pectin microparticles loaded with nanoemulsions as nanocomposites for wound healing.

This work combines natural polymers with nanoemulsions (NEs) to formulate nanocomposites as an innovative wound dressing. Spray-drying has been used to produce alginate-pectin in situ gelling powders as carriers for NEs loaded with curcumin (CCM), a model antimicrobial drug. The influence of NEs encapsulation in polymer-based microparticles was studied in terms of particle size distribution, morphology, and stability after spray-drying. NEs loading did not affect the size of microparticles which was around 3.5 µm, while the shape and surface morphology analyzed using scanning electron microscope (SEM) changed from irregular to spherical. Nanocomposites as dried powders were able to form a gel in less than 5 min when in contact with simulated wound fluid (SWF), while the value of moisture transmission of the in situ formed hydrogels allowed to promote good wound transpiration. Moreover, rheologic analyses showed that in situ formed gels loaded with NEs appeared more elastic than blank formulations. The in situ formed gel allowed the prolonged release of CCM-loaded NEs in the wound bed, reaching 100% in 24 h. Finally, powders cytocompatibility was confirmed by incubation with keratinocyte cells (HaCaT), proving that such nanocomposites can be considered a potential candidate for wound dressings.

In Situ Hydrogel Formulation for Advanced Wound Dressing: Influence of Co-Solvents and Functional Excipient on Tailored Alginate-Pectin-Chitosan Blend Gelation Kinetics, Adhesiveness, and Performance.

Chronic skin wounds affect more than 40 million patients worldwide, representing a huge problem for healthcare systems. This study elucidates the optimization of an in situ gelling polymer blend powder for biomedical applications through the use of co-solvents and functional excipients, underlining the possibility of tailoring microparticulate powder properties to generate, in situ, hydrogels with advanced properties that are able to improve wound management and patient well-being. The blend was composed of alginate, pectin, and chitosan (APC). Various co-solvents (ethanol, isopropanol, and acetone), and salt excipients (sodium bicarbonate and ammonium carbonate) were used to modulate the gelation kinetics, rheology, adhesiveness, and water vapor transmission rate of the gels. The use of co-solvents significantly influenced particle size (mean diameter ranging from 2.91 to 5.05 µm), depending on the solvent removal rate. Hydrogels obtained using ethanol were able to absorb over 15 times their weight in simulated wound fluid within just 5 min, whereas when sodium bicarbonate was used, complete gelation was achieved in less than 30 s. Such improvement was related to the internal microporous network typical of the particle matrix obtained with the use of co-solvents, whereas sodium bicarbonate was able to promote the formation of allowed particles. Specific formulations demonstrated an optimal water vapor transmission rate, enhanced viscoelastic properties, gel stiffness, and adhesiveness (7.7 to 9.9 kPa), facilitating an atraumatic removal post-use with minimized risk of unintended removal. Microscopic analysis unveiled that porous inner structures were influencing fluid uptake, gel formation, and transpiration. In summary, this study provided valuable insights for optimizing tailored APC hydrogels as advanced wound dressings for chronic wounds, including vascular ulcers, pressure ulcers, and partial and full-thickness wounds, characterized by a high production of exudate.

Recapsoma®: A Novel Mixture Based on Bergamot, Ipomoea Batatas, Policosanol Extracts and Liposomal Berberine for the Treatment of Hypercholesterolemia.

Cardiovascular disease (CVD) is considered one of the major causes of mortality worldwide. Epidemiological studies have shown that regular consumption of phenols is inversely associated with cardiovascular disease, and the use of nutraceuticals and functional foods can provide protective, preventive, and possibly curative effects in CVD. A novel mixture of different natural substances named Recapsoma® (bergamot, liposomal berberine, Ipomoea batatas, oleuropein, polycosanols, and vitamin E) has been produced, and its anti-dyslipidaemic efficacy has been tested, specifically studying the in vitro effects on the mechanisms of action underlying cholesterol synthesis, triglycerides, and LDL-cholesterol oxidation. The work has demonstrated the ability of this herbal extract mixture to inhibit the action of PCSK, ACAT, PAP, and HMGR and to increase the LDL receptor (LDLR), underlying the synergistic effect of the mixture over the single components. Such results suggest that the Recapsoma® mixture could be used as a tool for controlling hypercholesterolemia, and an alternative to statins, especially for those patients with metabolic syndrome.

Supercritical Antisolvent Technique for the Production of Breathable Naringin Powder.

Flavonoids are polyphenolic compounds largely present in fruits and vegetables possessing antioxidant properties, anti-inflammatory and antibacterial activities. Their use in clinical practice is very poor due to their low bioavailability, susceptibility to oxidation and degradation. Moreover, their slight solubility in biological fluids and a consequent low dissolution rate leads to an irregular absorption from solid dosage forms, even though, anti-inflammatory formulations could be used as support for several disease treatment, i.e. the COVID-19 syndrome. To improve flavonoid bioavailability particle size of the powder can be reduced to make it breathable and to promote the absorption in the lung tissues. Supercritical fluid based antisolvent technique has been used to produce naringin particles, with size, shape and density as well as free flowing properties able to fit inhalation needs. The dried particles are produced with the removal of the solvent at lower temperatures compared to the most used traditional micronization processes, such as spray drying. The best breathable fraction for naringin particles is obtained for particles with a d50~7 µm manufactured at 35 °C-150 bar and at 60 °C-130 bar, corresponding to 32.6% and 36.7% respectively. The powder is produced using a high CO2 molar fraction (0.99) that assure a better removal of the solvent. NuLi-1 cell line of immortalised bronchial epithelial cells adopted to evaluate powder cytotoxicity indicated after 24 h absence of toxicity at concentration of 25 µM.

Plant hairy roots for the production of extracellular vesicles with antitumor bioactivity.

Plant extracellular vesicles (EVs) concentrate and deliver different types of bioactive molecules in human cells and are excellent candidates for a next-generation drug delivery system. However, the lack of standard protocols for plant EV production and the natural variations of their biomolecular cargo pose serious limitation to their use as therapeutics. To overcome these issues, we set up a versatile and standardized procedure to purify plant EVs from hairy root (HR) cultures, a versatile biotechnological system, already successfully employed as source of bioactive molecules with pharmaceutical and nutraceutical relevance. Herewith, we report that HR of Salvia dominica represent an excellent platform for the production of plant EVs. In particular, EVs derived from S. dominica HRs are small round-shaped vesicles carrying typical EV-associated proteins such as cytoskeletal components, chaperon proteins and integral membrane proteins including the tetraspanin TET-7. Interestingly, the HR-derived EVs showed selective and strong pro-apoptotic activity in pancreatic and mammary cancer cells. These results reveal that plant hairy roots may be considered a new promising tool in plant biotechnology for the production of extracellular vesicles for human health.

Post-COVID Syndrome: The Research Progress in the Treatment of Pulmonary sequelae after COVID-19 Infection.

Post-COVID syndrome or long COVID is defined as the persistence of symptoms after confirmed SARS-CoV-2 infection, the pathogen responsible for coronavirus disease. The content herein presented reviews the reported long-term consequences and aftereffects of COVID-19 infection and the potential strategies to adopt for their management. Recent studies have shown that severe forms of COVID-19 can progress into acute respiratory distress syndrome (ARDS), a predisposing factor of pulmonary fibrosis that can irreversibly compromise respiratory function. Considering that the most serious complications are observed in the airways, the inhalation delivery of drugs directly to the lungs should be preferred, since it allows to lower the dose and systemic side effects. Although further studies are needed to optimize these techniques, recent studies have also shown the importance of in vitro models to recreate the SARS-CoV-2 infection and study its sequelae. The information reported suggests the necessity to develop new inhalation therapies in order to improve the quality of life of patients who suffer from this condition.

One-Step Fabrication of Novel Polyethersulfone-Based Composite Electrospun Nanofiber Membranes for Food Industry Wastewater Treatment.

Using an environmentally friendly approach for eliminating methylene blue from an aqueous solution, the authors developed a unique electrospun nanofiber membrane made of a combination of polyethersulfone and hydroxypropyl cellulose (PES/HPC). SEM results confirmed the formation of a uniformly sized nanofiber membrane with an ultrathin diameter of 168.5 nm (for PES/HPC) and 261.5 nm (for pristine PES), which can be correlated by observing the absorption peaks in FTIR spectra and their amorphous/crystalline phases in the XRD pattern. Additionally, TGA analysis indicated that the addition of HPC plays a role in modulating their thermal stability. Moreover, the blended nanofiber membrane exhibited better mechanical strength and good hydrophilicity (measured by the contact angle). The highest adsorption capacity was achieved at a neutral pH under room temperature (259.74 mg/g), and the pseudo-second-order model was found to be accurate. In accordance with the Langmuir fitted model and MB adsorption data, it was revealed that the adsorption process occurred in a monolayer form on the membrane surface. The adsorption capacity of the MB was affected by the presence of various concentrations of NaCl (0.1-0.5 M). The satisfactory reusability of the PES/HPC nanofiber membrane was revealed for up to five cycles. According to the mechanism given for the adsorption process, the electrostatic attraction was shown to be the most dominant in increasing the adsorption capacity. Based on these findings, it can be concluded that this unique membrane may be used for wastewater treatment operations with high efficiency and performance.

Exosomal CD73 from serum of patients with melanoma suppresses lymphocyte functions and is associated with therapy resistance to anti-PD-1 agents.

BACKGROUND: CD73 is an ectonucleotidase producing the immunosuppressor mediator adenosine. Elevated levels of circulating CD73 in patients with cancer have been associated with disease progression and poor response to immunotherapy. Immunosuppressive pathways associated with exosomes can affect T-cell function and the therapeutic efficacy of anti-programmed cell-death protein 1 (anti-PD-1) therapy. Here, we conducted a retrospective pilot study to evaluate levels of exosomal CD73 before and early during treatment with anti-PD-1 agents in patients with melanoma and its potential contribution to affect T-cell functions and to influence the clinical outcomes of anti-PD-1 monotherapy. METHODS: Exosomes were isolated by mini size exclusion chromatography from serum of patients with melanoma (n=41) receiving nivolumab or pembrolizumab monotherapy. Expression of CD73 and programmed death-ligand 1 (PD-L1) were evaluated on exosomes enriched for CD63 by on-bead flow cytometry. The CD73 AMPase activity was evaluated by mass spectrometry, also in the presence of selective inhibitors of CD73. Interferon (IFN)-γ production and granzyme B expression were measured in CD3/28 activated T cells incubated with exosomes in presence of the CD73 substrate AMP. Levels of CD73 and PD-L1 on exosomes were correlated with therapy response. Exosomes isolated from healthy subjects were used as control. RESULTS: Isolated exosomes carried CD73 on their surface, which is enzymatically active in producing adenosine. Incubation of exosomes with CD3/28 activated T cells in the presence of AMP resulted in a significant reduction of IFN-γ release, which was reversed by the CD73 inhibitor APCP or by the selective A2A adenosine receptor antagonist ZM241385. Expression levels of exosomal CD73 from serum of patients with melanoma were not significantly different from those in healthy subjects. Early on-treatment, expression levels of both CD73 and PD-L1 on exosomes isolated from patients receiving pembrolizumab or nivolumab monotherapy were significantly increased compared with baseline. Early during therapy exosomal PD-L1 increased in responders, while exosomal CD73 resulted significantly increased in non-responders. CONCLUSIONS: CD73 expressed on exosomes from serum of patients with melanoma produces adenosine and contributes to suppress T-cell functions. Early on-treatment, elevated expression levels of exosomal CD73 might affect the response to anti-PD-1 agents in patients with melanoma who failed to respond to therapy.

Floating Ricobendazole Delivery Systems: A 3D Printing Method by Co-Extrusion of Sodium Alginate and Calcium Chloride.

At present, the use of benzimidazole drugs in veterinary medicine is strongly limited by both pharmacokinetics and formulative issues. In this research, the possibility of applying an innovative semi-solid extrusion 3D printing process in a co-axial configuration was speculated, with the aim of producing a new gastro-retentive dosage form loaded with ricobendazole. To obtain the drug delivery system (DDS), the ionotropic gelation of alginate in combination with a divalent cation during the extrusion was exploited. Two feeds were optimized in accordance with the printing requirements and the drug chemical properties: the crosslinking ink, i.e., a water ethanol mixture containing CaCl2 at two different ratios 0.05 M and 0.1 M, hydroxyethyl cellulose 2% w/v, Tween 85 0.1% v/v and Ricobendazole 5% w/v; and alginate ink, i.e., a sodium alginate solution at 6% w/v. The characterization of the dried DDS obtained from the extrusion of gels containing different amounts of calcium chloride showed a limited effect on the ink extrudability of the crosslinking agent, which on the contrary strongly influenced the final properties of the DDS, with a difference in the polymeric matrix toughness and resulting effects on floating time and drug release.

Inulin-g-poly-D,L-lactide, a sustainable amphiphilic copolymer for nano-therapeutics.

Cancer therapies started to take a big advantage from new nanomedicines on the market. Since then, research tried to better understand how to maximize efficacy while maintaining a high safety profile. Polyethylene glycol (PEG), the gold standard for nanomedicines coating design, is a winning choice to ensure a long circulation and colloidal stability, while in some cases, patients could develop PEG-directed immunoglobulins after the first administration. This lead to a phenomenon called accelerated blood clearance (ABC effect), and it is correlated with clinical failure because of the premature removal of the nanosystem from the circulation by immune mechanism. Therefore, alternatives to PEG need to be found. Here, looking at the backbone structural analogy, the hydrophilicity, flexibility, and its GRAS status, the natural polysaccharide inulin (INU) was investigated as PEG alternative. In particular, the first family of Inulin-g-poly-D,L-lactide amphiphilic copolymers (INU-PLAs) was synthesized. The new materials were fully characterized from the physicochemical point of view (solubility, 1D and 2D NMR, FT-IR, UV-Vis, GPC, DSC) and showed interesting hybrid properties compared to precursors. Moreover, their ability in forming stable colloids and to serve as a carrier for doxorubicin were investigated and compared with the already well-known and well-characterized PEGylated counterpart, polyethylene glycol-b-poly-D,L-lactide (PEG-PLA). This preliminary investigation showed INU-PLA to be able to assemble in nanostructures less than 200 nm in size and capable of loading doxorubicin with an encapsulation efficiency in the same order of magnitude of PEG-PLA analogues.

Advanced printable hydrogels from pre-crosslinked alginate as a new tool in semi solid extrusion 3D printing process.

With the aim to overcome alginate shape fidelity issue during the semisolid extrusion 3D printing and matrix collapsing after drying, we speculated that a pre-crosslinking step of the alginate ink-gel with low amount of Ca+2 could improve the hydrogel performance. To verify this, the influence of pre-crosslinker concentration (10-25 mM) on the ink gel rheological properties were studied and flow behaviour and viscoelastic properties were determined. The developed ink gels were fully characterised by DSC and Magnetic Resonance Imaging (MRI). Moreover, extrudability and the shape retention of extruded forms after printing and after drying were studied. The rheological and MRI data, combined with the morphological analysis of printed forms allowed us to identify the relationship between printability, shape retention and shear thinning behaviour of gels, showing good extrudability for all the pre-crosslinked gels with a calcium concentration between 0.15 and 0.25, corresponding to both egg-box dimers and multimers interactions.

A Novel Three-Polysaccharide Blend In Situ Gelling Powder for Wound Healing Applications.

In this paper, alginate/pectin and alginate/pectin/chitosan blend particles, in the form of an in situ forming hydrogel, intended for wound repair applications, have been successfully developed. Particles have been used to encapsulate doxycycline in order to control the delivery of the drug, enhance its antimicrobial properties, and the ability to inhibit host matrix metalloproteinases. The presence of chitosan in the particles strongly influenced their size, morphology, and fluid uptake properties, as well as drug encapsulation efficiency and release, due to both chemical interactions between the polymers in the blend and interactions with the drug demonstrated by FTIR studies. In vitro antimicrobial studies highlighted an increase in antibacterial activity related to the chitosan amount in the powders. Moreover, in situ gelling powders are able to induce a higher release of IL-8 from the human keratinocytes that could stimulate the wound healing process in difficult-healing. Interestingly, doxycycline-loaded particles are able to increase drug activity against MMPs, with good activity against MMP-9 even at 0.5 µg/mL over 72 h. Such results suggest that such powders rich in chitosan could be a promising dressing for exudating wounds.