Biopolymer nanoparticle production for controlled release of biopharmaceuticals

Sensory Nerve Regulation via H3K27 Demethylation Revealed in Akermanite Composite Microspheres Repairing Maxillofacial Bone Defect

Maxillofacial bone defects exhibit intricate anatomy and irregular morphology, presenting challenges for effective treatment. This study aimed to address these challenges by developing an injectable bioactive composite microsphere, termed D-P-Ak (polydopamine-PLGA-akermanite), designed to fit within the defect site while minimizing injury. The D-P-Ak microspheres biodegraded gradually, releasing calcium, magnesium, and silicon ions, which, notably, not only directly stimulated the osteogenic differentiation of bone marrow mesenchymal stem cells (BMSCs) but also activated sensory nerve cells to secrete calcitonin gene-related peptide (CGRP), a key factor in bone repair. Moreover, the released CGRP enhanced the osteogenic differentiation of BMSCs through epigenetic methylation modification. Specifically, inhibition of EZH2 and enhancement of KDM6A reduced the trimethylation level of histone 3 at lysine 27 (H3K27), thereby activating the transcription of osteogenic genes such as Runx2 and Osx. The efficacy of the bioactive microspheres in bone repair is validated in a rat mandibular defect model, demonstrating that peripheral nerve response facilitates bone regeneration through epigenetic modification. These findings illuminated a novel strategy for constructing neuroactive osteo-inductive biomaterials with potential for further clinical applications.

Exosome-loaded hydrogels for craniofacial bone tissue regeneration

It is common for maladies and trauma to cause significant bone deterioration in the craniofacial bone, which can cause patients to experience complications with their appearance and their ability to function. Regarding grafting procedures' complications and disadvantages, the newly emerging field of tissue regeneration has shown promise. Tissue -engineered technologies and their applications in the craniofacial region are increasingly gaining prominence with limited postoperative risk and cost. MSCs-derived exosomes are widely applied in bone tissue engineering to provide cell-free therapies since they not only do not cause immunological rejection in the same way that cells do, but they can also perform a cell-like role. Additionally, the hydrogel system is a family of multipurpose platforms made of cross-linked polymers with considerable water content, outstanding biocompatibility, and tunable physiochemical properties for the efficient delivery of commodities. Therefore, the promising exosome-loaded hydrogels can be designed for craniofacial bone regeneration. This review lists the packaging techniques for exosomes and hydrogel and discusses the development of a biocompatible hydrogel system and its potential for exosome continuous delivery for craniofacial bone healing.

Berberine encapsulated phenylboronic acid-conjugated pullulan nanoparticles: Synthesis, characterization and anticancer activity validated in A431 skin cancer cells and 3D spheroids

Polysaccharide-based drug delivery systems are in high demand due to their biocompatibility, non-toxicity, and low-cost. In this study, sialic acid receptor targeted 4-carboxy phenylboronic acid modified pullulan-stearic acid conjugate (4-cPBA-PUL-SA) was synthesized and characterized for the delivery of Berberine (BBR). BBR-loaded 4-cPBA-PUL-SA nanoparticles (BPPNPs) were monodispersed (PDI: 0.238 ± 0.07), with an average hydrodynamic particle size of 191.6 nm and 73.6 % encapsulation efficiency. BPPNPs showed controlled BBR release and excellent colloidal stability, indicating their potential for drug delivery application. The cytotoxicity results indicated that BPPNPs exhibited dose and time-dependent cytotoxicity against human epidermoid carcinoma cells (A431) as well as 3D spheroids. Targeted BPPNPs demonstrated significantly higher anticancer activity compared to BBR and non-targeted BPNPs. The IC50 values for BPPNPs (2.29 μg/ml) were significantly lower than BPNPs (4.13 μg/ml) and BBR (19.61 μg/ml), indicating its potential for skin cancer treatment. Furthermore, CSLM images of A431 cells and 3D spheroids demonstrated that BPPNPs have higher cellular uptake and induced apoptosis compared to free BBR and BPNPs. In conclusion, BPPNPs demonstrate promising potential as an effective drug delivery system for skin cancer therapy.

Development of Vitamin C-Loaded Electrospun Nanofibers of Mixture of Polysaccharides of Pullulan/Xanthan Gum for Fast Dissolving Oral Film Applications

In this study, polysaccharide-based nanofibrous fast dissolving oral films (FDOFs) were developed using pullulan (PUL) and xanthan gum (XG) via electrospinning. The edible, continuous, and bead-free nanofibers with average diameters ranging from 181.17 nm to 260.84 nm were prepared. The morphological, thermal, mechanical, and water-soluble properties of the nanofibrous FDOFs were characterized. For prospective future applications of the developed PUL/XG FDOFs, a model nutrient of vitamin C (VC) was encapsulated into the FDOFs. The success of VC encapsulation was confirmed by Fourier transform infrared spectroscopy. The encapsulation efficiency of VC was above 85% by ultraviolet-visible spectrophotometer. The amorphous structure of PUL/XG in the nanofibers film was demonstrated by X-ray diffractometer. In addition, the edible FDOFs could dissolve in water within 3 s. The nanofibers film we prepared could be used as nutrient or drug carriers and edible packaging film.

Advances in Chitosan-based Drug Delivery Systems in Melanoma: A Narrative Review

Melanoma accounts for the minority of skin cancer cases. However, it has the highest mortality rate among the subtypes of skin cancer. At the early stages of the disease, patients show a good prognosis after the surgery, but developing metastases leads to a remarkable drop in patients' 5-year survival rate. Despite the advances made in the therapeutic approaches to this disease, melanoma treatment is still facing several obstacles. Systemic toxicity, water insolubility, instability, lack of proper biodistribution, inadequate cellular penetration, and rapid clearance are some of the challenges that should be addressed in the field of melanoma treatment. While various delivery systems have been developed to circumvent these challenges, chitosan-based delivery platforms have indicated significant success. Chitosan that is produced by the deacetylation of chitin can be formulated into different materials (e.g., nanoparticle, film, and hydrogel) due to its characteristics. Both in vitro and in vivo studies have reported that chitosan-based materials can be used in drug delivery systems while offering a solution for the common problems in this area, such as enhancing biodistribution and skin penetration as well as the sustained release of the drugs. Herein, we reviewed the studies concerning the role of chitosan as a drug delivery system in melanoma and discussed how these drug systems are used for delivering chemotherapeutic drugs (e.g., doxorubicin and paclitaxel), genes (e.g., TRAIL), and RNAs (e.g., miRNA199a and STAT3 siRNA) successfully. Furthermore, we take a look into the role of chitosan-based nanoparticles in neutron capture therapy.

Polysaccharide-based nanoassemblies: From synthesis methodologies and industrial applications to future prospects

Polysaccharides, due to their remarkable features, have gained significant prominence in the sustainable production of nanoparticles (NPs). High market demand and minimal production cost, compared to the chemically synthesised NPs, demonstrate a drive towards polysaccharide-based nanoparticles (PSNPs) benign to environment. Various approaches are used for the synthesis of PSNPs including cross-linking, polyelectrolyte complexation, and self-assembly. PSNPs have the potential to replace a wide diversity of chemical-based agents within the food, health, medical and pharmacy sectors. Nevertheless, the considerable challenges associated with optimising the characteristics of PSNPs to meet specific targeting applications are of utmost importance. This review provides a detailed compilation of recent accomplishments in the synthesis of PSNPs, the fundamental principles and critical factors that govern their rational fabrication, as well as various characterisation techniques. Noteworthy, the multiple use of PSNPs in different disciplines such as biomedical, cosmetics agrochemicals, energy storage, water detoxification, and food-related realms, is accounted in detail. Insights into the toxicological impacts of the PSNPs and their possible risks to human health are addressed, and efforts made in terms of PSNPs development and optimising strategies that allow for enhanced delivery are highlighted. Finally, limitations, potential drawbacks, market diffusion, economic viability and future possibilities for PSNPs to achieve widespread commercial use are also discussed.

Human beta defensin-2 loaded PLGA nanoparticles impregnated in collagen-chitosan composite scaffold for the management of diabetic wounds

Diabetic wound (DW) is the most devastating complication resulting in significant mortality and morbidity in diabetic patients. The standard treatment of DW care fails to address the prerequisites of treating DW owing to its multifactorial pathophysiology. Henceforth, developing a single treatment strategy to handle all the loopholes may effectively manage DW. The objective of the current study was to formulate Human beta defensin-2 (HBD-2) loaded Poly (lactic-co-glycolic acid) (PLGA) nanoparticle impregnated in collagen/chitosan (COL-CS) composite scaffolds for the accelerated healing of DW. Upon investigation, the developed biodegradable crosslinked scaffold possesses low matrix degradation, optimum porosity, and sustained drug release than the non-crosslinked scaffold. In vitro studies revealed that the HBD-2 COL-CS scaffold was biocompatible and accelerated cell migration and angiogenesis. The HBD-2 COL-CS scaffold showed significant antimicrobial activity in S. aureus, E. coli, and P. aeruginosa. The in vivo studies revealed that the HBD-2 COL-CS treated group accelerated healing compared to those in COL-CS and control groups. The ELISA results indicated a significant decrease in MMP-9, TNF-α, MPO, NAG, and NO with an increase in IL-10 in HBD-2 COL-CS treated group. The accelerated healing in HBD-2 COL-CS treated group might be due to the synergistic effects of PLGA (collagen synthesis and deposition and positive angiogenic effect), HBD-2 (anti-inflammatory, antibacterial, positive angiogenic effect, cell proliferation, and migration), COL (established wound healer and stabilizer) and CS (antibacterial, controlled drug release).

The applications of polysaccharides in dentistry

Polysaccharides are natural polymers widely present in animals, plants, and several microorganisms. Polysaccharides have remarkable properties, including easy extractions, degradability, and renewability, and have no apparent toxicity, making them ideal for biomedical applications. Moreover, polysaccharides are suitable for repairing oral tissue defects and treating oral diseases due to their excellent biocompatibility, biosafety, anti-inflammatory, and antibacterial properties. The oral cavity is a relatively complex environment vulnerable to numerous conditions, including soft tissue diseases, hard tissue disorders, and as well as soft and hard tissue diseases, all of which are complex to treat. In this article, we reviewed different structures of natural polysaccharides with high commercial values and their applications in treating various oral disease, such as drug delivery, tissue regeneration, material modification, and tissue repair.

A review on super-wettable porous membranes and materials based on bio-polymeric chitosan for oil-water separation

Appropriate surface wettability of membranes and materials are of an extreme importance for targeting separation of mixtures/emulsions such as oil from water or conversely water from oil. The development of super-wettable membranes and materials surfaces have shown remarkable potential for recovering water from oil-water emulsion while offering maximum resistance to fouling. The availability of clean and potable water has been regarded as an important global challenge for coming human generations. Oil and gas industry is continuously producing immense quantities of waste stream regarded as produced water which contains oil dispersed in water along with other several components. Treating such immense quantities of oily wastewater is of utmost need for recovering precious water for possible reuse or safe disposal. Various technologies have been developed for targeting the separation of oil-water emulsions or mixtures to harness useful potable water and oil as products. Membrane-based separations or use of porous materials such as mesh have been explored in literature for separation of oil-water mixtures/emulsions. Given the unique features of special hydrophilicity, ease of tunability, control of molecular weight, abundant availability, and potential for commercial scale up, chitosan has been extensively used for modifying membranes/meshes or preparing composites with other materials for oil-water separations. This review has described in detail the synthesis, methods of modification and application of chitosan-based super-wettable membranes/meshes and porous materials for oil-water separation. The special wettability features including super-hydrophobicity/superoleophilicity, super-oleophobicity/super-hydrophilicity and super-hydrophilicity/underwater super-oleophobicity of various chitosan-based membranes and materials have been discussed in detail in the review. The strategies for enhancing or developing special wettability for target specific applications have also been discussed. Finally, the challenges, their respective importance have been identified along with a discussion on possible solutions to these challenges.

Influence of the block copolypeptide surfactant structure on the size of polypeptide nanoparticles obtained by mini emulsion polymerisation

Polypetide nanoparticles obtained by miniemulsion polymerisation of amino acid N-carboxyanhydrides (NCA) are a novel class of tuneable bio-derived functional nano materials for potential applications in nutraceutics, agriculture, and medicine. This...

Physicochemical and release behaviour of phytochemical compounds based on black jamun pulp extracts-filled alginate hydrogel beads through vibration dripping extrusion

The phytochemical-rich extract obtained from black jamun pulp were encapsulated using vibrating dripping extrusion technique. The utilisation of alginate (AL) with four variations of core-shell material comprising gum Arabic (AL-GA), guar gum (AL-GG), pectin (AL-P) and xanthan gum (AL-X) was engaged to form calcium-alginate based lyophilised jamun extract encapsulated beads. It resulted that among four variations, lyophilised alginate with AL-GG based encapsulated jamun extract filled beads have better physicochemical characteristics and 95% encapsulation efficiency. The results revealed the morphological comparison of each variation. The release behaviour of AL-GG based beads has a higher release of total phenolics (TPC) and total anthocyanin content (TAC). The release kinetics model involving Ritger-Peppas and Higuchi model were applied for release TPC and TAC of all variations of beads. The Ritger-Peppas model was found best suitable in terms of average R² (0.965) and lowest χ² (0.0039). The release kinetics study showed that AL-GA based beads followed by AL-GG could also be the best suitable in release behaviour using simulated gastrointestinal fluids at 140-160 min. Overall, results shown the encapsulated Jamun beads have the best agro-industrial efficacy in form of phytochemical compounds based microparticles, holding decent antioxidant potential.

Foxtail millet prolamin as an effective encapsulant deliver curcumin by fabricating caseinate stabilized composite nanoparticles

The development of food proteins as effective delivery systems is of great significance for the encapsulation of active compounds. Foxtail millet prolamin (FP) has a high level of hydrophobic amino acids and proline, meets the basic characteristics of delivery system, and was described here for the first time as an effective delivery system for the encapsulation of curcumin. The interaction between FP and curcumin was confirmed by fluorescence spectroscopy, showing the joint driving of hydrophobic forces and hydrogen bonds. Curcumin-loaded caseinate-stabilized FP nanodispersions were prepared by anti-solvent/evaporation method. The mean particle size was about 220-235 nm, sharing features of a spherical shape, uniform particle size, and smooth surfaces. High level of curcumin was encapsulated in the FP-based nanoparticles, exhibiting high particle yield (>88.4%) and encouraging encapsulation efficiency (>71.3%). X-ray diffraction and Fourier transform infrared spectroscopy demonstrated that the encapsulated curcumin was amorphous state and interacted with proteins via non-covalent bonds. The nano-sized particles can effectively prevent the degradation of curcumin during heat treatment, and significantly enhance the antioxidant and anti-tumor properties. This study provides a new encapsulant for effective protection and targeted delivery of hydrophobic active biomolecules.

Chitosan-tripolyphosphate nanoparticles designed to encapsulate polyphenolic compounds for biomedical and pharmaceutical applications - A review

Plant-based polyphenols are natural compounds, present in fruits and vegetables. During recent years, polyphenols have gained special attention due to their nutraceutical and pharmacological activities for the prevention and treatment of human diseases. Nevertheless, their photosensitivity and low bioavailability, rapid metabolism and short biological half-life represent the major limitations for their use, which could be overcome by polyphenols encapsulation (flavonoids and non-flavonoids) into chitosan (CS)-tripolyphosphate (TPP) based nanoparticles (NP). In this review, we particularly focused on the ionic gelation method for the NP design. This contribution exhaustively discusses and compares results of scientific reports published in the last decade referring to ionic gelation applied for the protection, controlled and site-directed delivery of polyphenols. As a consequence, CS-TPP NP would constitute true platforms to transport polyphenols, or a combination of them, to be used for the designing of a new generation of drugs or nutraceuticals.

Tailoring Alginate/Chitosan Microparticles Loaded with Chemical and Biological Agents for Agricultural Application and Production of Value-Added Foods

This work reviews the recent development of biopolymer-based delivery systems for agricultural application. Encapsulation into biopolymer microparticles ensures the protection and targeted delivery of active agents while offering controlled release with higher efficiency and environmental safety for ecological and sustainable plant production. Encapsulation of biological agents provides protection and increases its survivability while providing an environment safe for growth. The application of microparticles loaded with chemical and biological agents presents an innovative way to stimulate plant metabolites synthesis. This enhances plants’ defense against pests and pathogens and results in the production of higher quality food (i.e., higher plant metabolites share). Ionic gelation was presented as a sustainable method in developing biopolymeric microparticles based on the next-generation biopolymers alginate and chitosan. Furthermore, this review highlights the advantages and disadvantages of advanced formulations against conventional ones. The significance of plant metabolites stimulation and their importance in functional food production is also pointed out. This review offers guidelines in developing biopolymeric microparticles loaded with chemical and biological agents and guidelines for the application in plant production, underlining its effect on the plant metabolites synthesis.

In vitro Toxico-genomics of Etoposide Loaded Gelatin Nanoparticles and Its in-vivo Therapeutic Potential: Pharmacokinetics, Biodistribution and Tumor Regression in Ehrlich Ascites Carcinoma (EAC) Mice Model

Globally, breast cancer is the foremost cause of mortality among women detected with cancer, with 21% diagnosed in India alone. Etoposide loaded gelatin nanoparticles (EGNP) were prepared and its physical characterization (size:150nm±0.241; zeta potential −29.32 mV) was done along with in-vitro studies to assess biotoxicity, intracellular ROS, cell cycle arrest and death caused by EGNPs. We report the molecular pathways induced by EGNP in-vitro, pharmacokinetics, biodistribution and tumor regression in-vivo in Balb/c mice.Gene expression profiling of Bax, Bcl2, p53, Caspase-3, RIPK1, RIPK3 and ß-actin as internal control were done by RT-PCR wherein Etoposide and EGNP treated MCF-7 cells showed higher expressions of apoptotic genes-Bax, p53, caspase-3, lower expression of anti-apoptotic gene-Bcl2 when compared to control. Enhanced expression of necroptosis-RIPK1 were observed, while RIPK3 was insignificant. Since, RIPK1 regulates necroptosis and apoptosis, expression of apoptotic markers confirmed apoptotic molecular mechanisms. Negligible hemolysis of Gelatin nanoparticles (GNP), and EGNP at selected dosages confirmed biocompatibility. In vivo pharmacokinetics and biodistribution were done by 99Tc-labelled nanoparticles indicating increased circulation of EGNPs, allowing accumulation at the tumor site by Enhanced permeability and retention (EPR) phenomena. Tumor regression indicates the efficacy of EGNP by reducing the tumor burden when compared to void GNP and Etop per se, resulting in increased life span. High biocompatibility and bio-efficacy of EGNPs prove their therapeutic potential in cancer treatment.

Chemical and physical Chitosan modification for designing enzymatic industrial biocatalysts: How to choose the best strategy?

Chitosan is one of the most abundant natural polymer worldwide, and due to its inherent characteristics, its use in industrial processes has been extensively explored. Because it is biodegradable, biocompatible, non-toxic, hydrophilic, cheap, and has good physical-chemical stability, it is seen as an excellent alternative for the replacement of synthetic materials in the search for more sustainable production methodologies. Thus being, a possible biotechnological application of Chitosan is as a direct support for enzyme immobilization. However, its applicability is quite specific, and to overcome this issue, alternative pretreatments are required, such as chemical and physical modifications to its structure, enabling its use in a wider array of applications. This review aims to present the topic in detail, by exploring and discussing methods of employment of Chitosan in enzymatic immobilization processes with various enzymes, presenting its advantages and disadvantages, as well as listing possible chemical modifications and combinations with other compounds for formulating an ideal support for this purpose. First, we will present Chitosan emphasizing its characteristics that allow its use as enzyme support. Furthermore, we will discuss possible physicochemical modifications that can be made to Chitosan, mentioning the improvements obtained in each process. These discussions will enable a comprehensive comparison between, and an informed choice of, the best technologies concerning enzyme immobilization and the application conditions of the biocatalyst.

Natural polymeric nanocarriers in malignant glioma drug delivery and targeting

Among all central nervous diseases, malignant glioma is a crucial part that deserves more attention since high fatality and disability rate. There are several therapeutic strategies applied to the treatment of malignant glioma, especially certain chemotherapy-related treatments. However, the existence of the blood-brain barrier (BBB) seriously hinders the strategy's progress, so how to escape from the barriers is a fascinating question. Herein, we comprehensively discussed the details of malignant glioma and the BBB's functional morphology and summarized several routes bypassing the BBB. Additionally, since possessing excellent properties for drug delivery, we provided an insight into various promising natural polymeric materials and highlighted their applications in the treatment of malignant glioma.

Alginate-based hydrogels for cancer therapy and research

Cancer is a major health issue concerning to all of us. Current treatment options are still limited due to not-selective action. Encapsulation is contemplated as an innovative approach to address systemic toxicity and tumor resistance caused by traditional therapies, while increasing encapsulated compounds bioavailability. The coating material of capsules strongly determines the success of the system. Since alginate has been proved non-toxic, biocompatible and biodegradable, it is considered a potential vehicle for therapeutic factors encapsulation. Besides, it has the particular ability to form hydrogels, which hold a high-water content and greatly resemble to natural soft tissues. The present review exposes the state-of-the-art and the most sophisticated alginate-based systems for cancer therapy and research. It begins with an overview of alginate hydrogels and the qualities that make them especially suitable for biomedical applications. In the following section, the application of alginate hydrogels as pioneering strategies for cancer treatment is described. Several examples of alginate-based delivery systems of therapeutic drugs, proteins and nucleic acids are provided. Significant emphasis is placed in both oral delivery systems and colorectal cancer therapy. Moreover, the role of alginate 3-D scaffolds for both cell culture and delivery is explained. Lastly, other applications of alginate-based hydrogels such as tumor biomarkers immunosensing and fluorescent surgical marker are included.

Aerosolized drug-loaded nanoparticles targeting migration inhibitory factors inhibit Pseudomonas aeruginosa-induced inflammation and biofilm formation

Aim: Macrophage migration inhibitory factor (MIF) is a pro-inflammatory cytokine, which has been shown to promote disease severity in cystic fibrosis. Methods: In this study, aerosolized drug-loaded nanoparticles containing SCD-19, an inhibitor of MIF's tautomerase enzymatic activity, were developed and characterized. Results: The aerosolized nanoparticles had an optimal droplet size distribution for deep lung deposition, with a high degree of biocompatibility and significant cellular uptake. Conclusion: For the first time, we have developed an aerosolized nano-formulation against MIF's enzymatic activity that achieved a significant reduction in the inflammatory response of macrophages, and inhibited Pseudomonas aeruginosa biofilm formation on airway epithelial cells. This represents a potential novel adjunctive therapy for the treatment of P. aeruginosa infection in cystic fibrosis.

Three Dimensional Printing Bilayer Membrane Scaffold Promotes Wound Healing

Full-thickness skin wounds are common and could be a heavy physical and economic burden. With the development of three dimensional (3D) printing technology, skin-like constructs have been fabricated for skin wound healing and regeneration. Although the 3D printed skin has great potential and enormous advantages before vascular networks can be well-constructed, living cells are not recommended for 3D skin printing for in vivo applications. Herein, we designed and printed a bilayer membrane (BLM) scaffold consisting of an outer poly (lactic-co-glycolic acid) (PLGA) membrane and a lower alginate hydrogel layer, which respectively mimicked the skin epidermis and dermis. The multi-porous alginate hydrogel of the BLM scaffolds promoted cell adhesion and proliferation in vitro, while the PLGA membrane prevented bacterial invasion and maintained the moisture content of the hydrogel. Skin regeneration using the bilayer scaffold was compared with that of PLGA, alginate hydrogel and the untreated defect in vivo. Tissue samples were analyzed using histopathological and immunohistochemical staining of CD31. In addition, mRNA expression levels of collagen markers [collagen type 1 alpha 1 (COL1a1) and collagen type 3 alpha 1 (COL3a1)] and inflammatory markers [interleukin-1β (IL-1β), as well as tumor necrosis factor (TNF-α)] were measured. Conclusively, the application of BLM scaffold resulted in highest levels of best skin regeneration by increasing neovascularization and boosting collagen I/III deposition. Taken together, the 3D-printed BLM scaffolds can promote wound healing, and are highly suitable for a wide range of applications as wound dressings or skin substitutes.

Use of Nanoparticles in Tissue Engineering and Regenerative Medicine

Advances in nanoparticle (NP) production and demand for control over nanoscale systems have had significant impact on tissue engineering and regenerative medicine (TERM). NPs with low toxicity, contrasting agent properties, tailorable characteristics, targeted/stimuli-response delivery potential, and precise control over behavior (via external stimuli such as magnetic fields) have made it possible their use for improving engineered tissues and overcoming obstacles in TERM. Functional tissue and organ replacements require a high degree of spatial and temporal control over the biological events and also their real-time monitoring. Presentation and local delivery of bioactive (growth factors, chemokines, inhibitors, cytokines, genes etc.) and contrast agents in a controlled manner are important implements to exert control over and monitor the engineered tissues. This need resulted in utilization of NP based systems in tissue engineering scaffolds for delivery of multiple growth factors, for providing contrast for imaging and also for controlling properties of the scaffolds. Depending on the application, materials, as polymers, metals, ceramics and their different composites can be utilized for production of NPs. In this review, we will cover the use of NP systems in TERM and also provide an outlook for future potential use of such systems.

Immobilization of Dextranase Using Anionic Natural Polymer Alginate as a Matrix for the Degradation of a Long-Chain Biopolymer (Dextran)

Alginate is an inexpensive, nontoxic, valuable biopolymer utilized in the study for the immobilization of commercially applicable biocatalyst dextranase. Dextranase was immobilized by an entrapment method, and alginate hydrogel spheres were synthesized after optimizing several parameters. A sodium alginate concentration of 4.0% was noticed to be suitable along with a calcium chloride concentration of 0.2 molar after providing a curing time of 20 minutes. After comparing the characteristics of the entrapped enzyme with those of the soluble one, it was observed that the characteristics were more or less the same except for the change in reaction time which was noticed to be prolonged in the case of entrapped dextranase while the change in temperature and pH optima was not observed. The variation in Vmax and Km values of dextranase after entrapment was also noted. However, after extensive stability examination studies, it was found that dextranase became more stable after entrapment; as a result, it retained more than 50% of its original activity at elevated temperature even after exposure for about 2.0 hours. The reusability of dextranase was up to 7.0 cycles after performing catalytic activity under constant condition.

Active Targeting of Cancer Cells by Nanobody Decorated Polypeptide Micelle with Bio-orthogonally Conjugated Drug

Polypeptides are promising carriers for chemotherapeutics: they have minimal toxicity, can be recombinantly synthesized with precise control over molecular weight, and enhance drug pharmacokinetics as self-assembled nanoparticles. Polypeptide-based systems also provide the ability to achieve active targeting with genetically encoded targeting ligands. While passive targeting promotes accumulation of nanocarriers in solid tumors, active targeting provides an additional layer of tunable control and widens the therapeutic window. However, fusion of most targeting proteins to polypeptide carriers exposes the limitations of this approach: the residues that are used for drug attachment are also promiscuously distributed on protein surfaces. We present here a universal methodology to solve this problem by the site-specific attachment of extrinsic moieties to polypeptide drug delivery systems without cross-reactivity to fused targeting domains. We incorporate an unnatural amino acid, p-acetylphenylalanine, to provide a biorthogonal ketone for attachment of doxorubicin in the presence of reactive amino acids in a nanobody-targeted, elastin-like polypeptide nanoparticle. These nanoparticles exhibit significantly greater cytotoxicity than nontargeted controls in multiple cancer cell lines.

Topical application of phenytoin or nifedipine-loaded PLGA microspheres promotes periodontal regeneration in vivo

OBJECTIVES

Gingival recession and alveolar bone loss are common manifestations of periodontitis. Periodontal regeneration is the ideal strategy for rehabilitating periodontal tissue defects and preventing tooth loss. The present study examined whether localized, topical application of gingival overgrowth-inducing drugs, phenytoin, nifedipine or cyclosporine, induces periodontal regeneration.

METHODS

Polylactic-co-glycolic acid (PLGA) was used as the carrier for preparation of phenytoin, nifedipine or cyclosporine-loaded PLGA microspheres, using an oil-in-water emulsification technique. The drug-loaded microspheres were delivered to periodontal defects created on alveolar ridges mesial to the first maxillary molars of Sprague-Dawley rats. After eight weeks, the operation area in each rat, including the maxillary molars and periodontal tissues, was harvested and evaluated by micro-computed tomography, histochemical and immunohistochemical analyses.

RESULTS

Physical parameters representative of periodontal regeneration, including the length of new alveolar bone (p < 0.01) and the area of new alveolar bone (p < 0.01) were significantly improved in the phenytoin group. Compared to other groups, the phenytoin group demonstrated increased expression of COL-1, VEGF-A, osteoblast and osteoclast markers (BMP-2, TGF-β1, OCN and TRAP staining), as well as decreased expression of MMP-8.

CONCLUSIONS

Results of the present study provided new evidence that localized, controlled release of phenytoin confers therapeutic benefits toward gingival recession and alveolar bone loss. Phenytoin appears to be a promising drug that promotes periodontal regeneration.

Biodegradable Polymeric Nanoparticles for Therapeutic Cancer Treatments

Polymeric nanoparticles have tremendous potential to improve the efficacy of therapeutic cancer treatments by facilitating targeted delivery to a desired site. The physical and chemical properties of polymers can be tuned to accomplish delivery across the multiple biological barriers required to reach diverse subsets of cells. The use of biodegradable polymers as nanocarriers is especially attractive, as these materials can be designed to break down in physiological conditions and engineered to exhibit triggered functionality when at a particular location or activated by an external source. We present how biodegradable polymers can be engineered as drug delivery systems to target the tumor microenvironment in multiple ways. These nanomedicines can target cancer cells directly, the blood vessels that supply the nutrients and oxygen that support tumor growth, and immune cells to promote anticancer immunotherapy.

PLGA based drug delivery systems: Promising carriers for wound healing activity

Wound treatment remains one of the most prevalent and economically burdensome healthcare issues in the world. Current treatment options are limited and require repeated administrations which led to the development of new therapeutics to satisfy the unmet clinical needs. Many potent wound healing agents were discovered but most of them are fragile and/or sensitive to in vivo conditions. Poly(lactic-co-glycolic acid) (PLGA) is a widely used biodegradable polymer approved by food and drug administration and European medicines agency as an excipient for parenteral administrations. It is a well-established drug delivery system in various medical applications. The aim of the current review is to elaborate the applications of PLGA based drug delivery systems carrying different wound healing agents and also present PLGA itself as a wound healing promoter. PLGA carriers encapsulating drugs such as antibiotics, anti-inflammatory drugs, proteins/peptides, and nucleic acids targeting various phases/signaling cycles of wound healing, are discussed with examples. The combined therapeutic effects of PLGA and a loaded drug on wound healing are also mentioned.

Modeling of the Nanoparticles Absorption Under a Gastrointestinal Simulated Ambient Condition

Proanthocyanidins (PAs) have several bioactivities, but they are unstable in the digestive tract and possess low bioavailability. Nanoencapsulation stabilizes these compounds for oral administration. The intestinal absorption of grape seed and skin extracts, and the poly-lactic acid (PLA) nanoparticles loaded with such extracts was modeled, taking into consideration physicochemical process parameters, evaluating the PAs concentration profile in the human small intestine. Density (ρ), solubility, viscosity (μ), diffusion coefficient (D), and the global mass transfer coefficient (K) for both substrates were estimated, simulating their passing from the intestine into the blood at 37°C. For the seed and skin extracts encapsulated in PLA the physicochemical parameters were: D = 1.81 × 10^^-5 and D = 5.72 × 10^^-5 cm²/s; K = 3.4 × 10^^-3 and K = 2.47 × 10^^-4 cm/s, respectively. Lower resistance was offered by the seed extract than by skin extracts (nanoencapsulated), which was explained by differences in structural composition, and average molecular weight of the two kinds of extracts, which should be more favorable to the mass transfer in comparison to the raw extracts. The concentration profile of grape extracts in the small intestine was modeled through a pure convection model, and the encapsulated extract on PLA nanoparticles using a mixed regime model, which described the process of dissolution and absorption of the grape extracts from the intestine to the blood stream. The absorbed fraction predicted by the model was 42.7 and 24.2% for seed and skin extracts, respectively. Those values increased to 100% for both extracts after the simulation with the nanoencapsulated extracts. Consequently, extract encapsulation should produce a significant increase in intestinal absorption.

Development of chitosan-sodium phytate nanoparticles as a potent antibacterial agent

Chitosan nanoparticles have attracted considerable attention as a potential carrier for food and pharmaceutical applications. Herein, using natural sodium phytate as a gelation agent, we developed a new type of green and biocompatible chitosan nanoparticles. We discovered that the chitosan-sodium phytate nanoparticles exhibited potent antibacterial activities. The chitosan-sodium phytate nanoparticles prepared from low molecular weight (LMW, 140±7kDa) and medium molecular weight (MMW, 454±21kDa) chitosan were spherical. Under optimum conditions-with a ratio of LMW chitosan to sodium phytate of 24:1 and MMW chitosan to sodium phytate of 21:1-the sizes of the LMW and MMW chitosan nanoparticles were 20-80 and 80-100nm, respectively, as observed by transmission electron microscopy. The formation mechanism of chitosan nanoparticles occurred through both electrostatic interactions and hydrogen bonds. No cytotoxicity for normal liver cells was found in chitosan-sodium phytate nanoparticles measured by methyl thiazolyl tetrazolium assay. Furthermore, the antimicrobial assays indicated that the antimicrobial activity of the LMW chitosan nanoparticles was greater than that of MMW chitosan nanoparticles. The minimum inhibition concentration values and half inhibiting concentration of LMW chitosan-sodium phytate nanoparticles for Escherichia coli were 1.5 and 0.8mg/mL, respectively. In addition, the antimicrobial activity of chitosan nanoparticles against Gram-negative bacteria was better than that against Gram-positive bacteria. The newly developed chitosan-sodium phytate nanoparticles could be used as a potential antibacterial agent.

Poly(lactic acid)-based particulate systems are promising tools for immune modulation

Poly(lactic acid) (PLA) is one of the most successful and versatile polymers explored for controlled delivery of bioactive molecules. Its attractive properties of biodegradability and biocompatibility in vivo have contributed in a meaningful way to the approval of different products by the FDA and EMA for a wide range of biomedical and pharmaceutical applications, in the past two decades. This polymer has been widely used for the preparation of particles as delivery systems of several therapeutic molecules, including vaccines. These PLA vaccine carriers have shown to induce a sustained and targeted release of different bacterial, viral and tumor-associated antigens and adjuvants in vivo, triggering distinct immune responses. The present review intends to highlight and discuss the major advantages of PLA as a promising polymer for the development of potent vaccine delivery systems against pathogens and cancer. It aims to provide a critical discussion based on preclinical data to better understand the major effect of PLA-based carrier properties on their interaction with immune cells and thus their role in the modulation of host immunity.

STATEMENT OF SIGNIFICANCE

During the last decades, vaccination has had a great impact on global health with the control of many severe diseases. Polymeric nanosystems have emerged as promising strategies to stabilize vaccine antigens, promoting their controlled release to phagocytic cells, thus avoiding the need for multiple administrations. One of the most promising polymers are the aliphatic polyesters, which include the poly(lactic acid). This is a highly versatile biodegradable and biocompatible polymer. Products containing this polymer have already been approved for all food and some biomedical applications. Despite all favorable characteristics presented above, PLA has been less intensively discussed than other polymers, such as its copolymer PLGA, including regarding its application in vaccination and particularly in tumor immunotherapy. The present review discusses the major advantages of poly(lactic acid) for the development of potent vaccine delivery systems, providing a critical view on the main properties that determine their effect on the modulation of immune cells.

Nanocarriers from GRAS Zein Proteins to Encapsulate Hydrophobic Actives

One factor limiting the expansion of nanomedicines has been the high cost of the materials and processes required for their production. We present a continuous, scalable, low cost nanoencapsulation process, Flash Nanoprecipitation (FNP) that enables the production of nanocarriers (NCs) with a narrow size distribution using zein corn proteins. Zein is a low cost, GRAS protein (having the FDA status of "Generally Regarded as Safe") currently used in food applications, which acts as an effective encapsulant for hydrophobic compounds using FNP. The four-stream FNP configuration allows the encapsulation of very hydrophobic compounds in a way that is not possible with previous precipitation processes. We present the encapsulation of several model active compounds with as high as 45 wt % drug loading with respect to zein concentration into ∼100 nm nanocarriers. Three examples are presented: (1) the pro-drug antioxidant, vitamin E-acetate, (2) an anticholera quorum-sensing modulator CAI-1 ((S)-3-hydroxytridecan-4-one; CAI-1 that reduces Vibrio cholerae virulence by modulating cellular communication), and (3) hydrophobic fluorescent dyes with a range of hydrophobicities. The specific interaction between zein and the milk protein, sodium caseinate, provides stabilization of the NCs in PBS, LB medium, and in pH 2 solutions. The stability and size changes in the three media provide information on the mechanism of assembly of the zein/active/casein NC.

Seaweed Polysaccharide-Based Nanoparticles: Preparation and Applications for Drug Delivery

In recent years, there have been major advances and increasing amounts of research on the utilization of natural polymeric materials as drug delivery vehicles due to their biocompatibility and biodegradability. Seaweed polysaccharides are abundant resources and have been extensively studied for several biological, biomedical, and functional food applications. The exploration of seaweed polysaccharides for drug delivery applications is still in its infancy. Alginate, carrageenan, fucoidan, ulvan, and laminarin are polysaccharides commonly isolated from seaweed. These natural polymers can be converted into nanoparticles (NPs) by different types of methods, such as ionic gelation, emulsion, and polyelectrolyte complexing. Ionic gelation and polyelectrolyte complexing are commonly employed by adding cationic molecules to these anionic polymers to produce NPs of a desired shape, size, and charge. In the present review, we have discussed the preparation of seaweed polysaccharide-based NPs using different types of methods as well as their usage as carriers for the delivery of various therapeutic molecules (e.g., proteins, peptides, anti-cancer drugs, and antibiotics). Seaweed polysaccharide-based NPs exhibit suitable particle size, high drug encapsulation, and sustained drug release with high biocompatibility, thereby demonstrating their high potential for safe and efficient drug delivery.

Polymeric Nanoparticles for Cancer Photodynamic Therapy

In chemotherapy a fine balance between therapeutic and toxic effects needs to be found for each patient, adapting standard combination protocols each time. Nanotherapeutics has been introduced into clinical practice for treating tumors with the aim of improving the therapeutic outcome of conventional therapies and of alleviating their toxicity and overcoming multidrug resistance. Photodynamic therapy (PDT) is a clinically approved, minimally invasive procedure emerging in cancer treatment. It involves the administration of a photosensitizer (PS) which, under light irradiation and in the presence of molecular oxygen, produces cytotoxic species. Unfortunately, most PSs lack specificity for tumor cells and are poorly soluble in aqueous media, where they can form aggregates with low photoactivity. Nanotechnological approaches in PDT (nanoPDT) can offer a valid option to deliver PSs in the body and to solve at least some of these issues. Currently, polymeric nanoparticles (NPs) are emerging as nanoPDT system because their features (size, surface properties, and release rate) can be readily manipulated by selecting appropriate materials in a vast range of possible candidates commercially available and by synthesizing novel tailor-made materials. Delivery of PSs through NPs offers a great opportunity to overcome PDT drawbacks based on the concept that a nanocarrier can drive therapeutic concentrations of PS to the tumor cells without generating any harmful effect in non-target tissues. Furthermore, carriers for nanoPDT can surmount solubility issues and the tendency of PS to aggregate, which can severely affect photophysical, chemical, and biological properties. Finally, multimodal NPs carrying different drugs/bioactive species with complementary mechanisms of cancer cell killing and incorporating an imaging agent can be developed. In the following, we describe the principles of PDT use in cancer and the pillars of rational design of nanoPDT carriers dictated by tumor and PS features. Then we illustrate the main nanoPDT systems demonstrating potential in preclinical models together with emerging concepts for their advanced design.

Chitosan: An Update on Potential Biomedical and Pharmaceutical Applications

Chitosan is a natural polycationic linear polysaccharide derived from chitin. The low solubility of chitosan in neutral and alkaline solution limits its application. Nevertheless, chemical modification into composites or hydrogels brings to it new functional properties for different applications. Chitosans are recognized as versatile biomaterials because of their non-toxicity, low allergenicity, biocompatibility and biodegradability. This review presents the recent research, trends and prospects in chitosan. Some special pharmaceutical and biomedical applications are also highlighted.