Microfluidic fabrication of alendronate-loaded chitosan nanoparticles for enhanced osteogenic differentiation of stem cells

Synthesis and application of chitosan nanoparticles for bone tissue regeneration

Bone defects, resulting from trauma, tumor removal, infection, or congenital anomalies, are increasingly prevalent in clinical practice. Progress in bone tissue engineering has significantly advanced bone regeneration techniques. Chitosan-based nanoparticles (ChNPs) have emerged as a promising drug delivery system due to their inherent ability to enhance bone regeneration. These nanoparticles can extend the activity of osteogenic factors while ensuring their controlled release. Common synthesis methods for ChNPs include ionic gelation, complex coacervation, and polyelectrolyte complexation. ChNPs have demonstrated effectiveness in bone regeneration by delivering osteogenic agents, including DNA/RNA, proteins, and therapeutics. This review provides a comprehensive analysis of recent studies on ChNPs in bone regeneration, sourced from the PubMed database. It examines their synthesis techniques, advantages as drug delivery systems, incorporation into scaffold materials, and the challenges that remain in the field.

One-Pot Microfluidics to Engineer Chitosan Nanoparticles Conjugated with Antimicrobial Peptides Using "Photoclick" Chemistry: Validation Using the Gastric Bacterium Helicobacter pylori

Surface bioconjugation of antimicrobial peptides (AMP) onto nanoparticles (AMP-NP) is a complex, multistep, and time-consuming task. Herein, a microfluidic system for the one-pot production of AMP-NP was developed. Norbornene-modified chitosan was used for NP production (NorChit-NP), and thiolated-AMP was grafted on their surface via thiol-norbornene "photoclick" chemistry over exposure of two parallel UV LEDs. The MSI-78A was the AMP selected due to its high activity against a high priority (level 2) antibiotic-resistant gastric pathogen: Helicobacter pylori (H. pylori). AMP-NP (113 ± 43 nm; zeta potential 14.3 ± 7 mV) were stable in gastric settings without a cross-linker (up to 5 days in pH 1.2) and bactericidal against two highly pathogenic H. pylori strains (1011 NP/mL with 96 μg/mL MSI-78A). Eradication was faster for H. pylori 26695 (30 min) than for H. pylori J99 (24 h), which was explained by the lower minimum bactericidal concentration of soluble MSI-78A for H. pylori 26695 (32 μg/mL) than for H. pylori J99 (128 μg/mL). AMP-NP was bactericidal by inducing H. pylori cell membrane alterations, intracellular reorganization, generation of extracellular vesicles, and leakage of cytoplasmic contents (transmission electron microscopy). Moreover, NP were not cytotoxic against two gastric cell lines (AGS and MKN74, ATCC) at bactericidal concentrations. Overall, the designed microfluidic setup is a greener, simpler, and faster approach than the conventional methods to obtain AMP-NP. This technology can be further explored for the bioconjugation of other thiolated-compounds.

Microfluidic-assisted preparation of PLGA nanoparticles loaded with insulin: a comparison with double emulsion solvent evaporation method

Poly lactic-co-glycolic acid (PLGA) is an ideal polymer for the delivery of small and macromolecule drugs. Conventional preparation methods of PLGA nanoparticles (NPs) result in poor control over NPs properties. In this research, a microfluidic mixer was designed to produce insulin-loaded PLGA NPs with tuned properties. Importantly; aggregation of the NPs through the mixer was diminished due to the coaxial mixing of the precursors. The micromixer allowed for the production of NPs with small size and narrow size distribution compared to the double emulsion solvent evaporation (DESE) method. Furthermore, encapsulation efficiency and loading capacity indicated a significant increase in optimized NPs produced through the microfluidic method in comparison to DESE method. NPs prepared by the microfluidic method were able to achieve a more reduction of trans-epithelial electrical resistance values in the Caco-2 cells compared to those developed by the DESE technique that leads to greater paracellular permeation. Compatibility and interaction between components were evaluated by differential scanning calorimetry and fourier transform infrared analysis. Also, the effect of NPs on cell toxicity was investigated using MTT test. Numerical simulations were conducted to analyze the effect of mixing patterns on the properties of the NPs. It was revealed that by decreasing flow rate ratio, i.e. flow rate of the organic phase to the flow rate of the aqueous phase, mixing of the two streams increases. As an alternative to the DESE method, high flexibility in modulating hydrodynamic conditions of the microfluidic mixer allowed for nanoassembly of NPs with superior insulin encapsulation at smaller particle sizes.

Ca-AlN MOFs-loaded chitosan/gelatin scaffolds; a dual-delivery system for bone tissue engineering applications

Creating a scaffold for bone tissue engineering that is bioactive and capable of acting as a local-dual delivery system, releasing bioactive molecules and regulating the bone remodeling process to achieve balanced bone resorption and formation, is a significant challenge. The objective of this research is to create a composite scaffold using chitosan/gelatin (CHS/Gel) and the calcium (Ca)-alendronate (ALN) metal-organic frameworks (MOFs). The scaffold will act as a dual-delivery system, releasing Ca ions and ALN to regulate bone formation. Ca-ALN MOF nanoparticles (NPs) were prepared in mild conditions and studied by FTIR, XRD, FESEM, and TGA. Ca-ALN NPs-loaded CHS/Gel scaffolds were opportunely fabricated through freeze-drying approach. Physicochemical features of the scaffolds after incorporating NPs equated by CHS/Gel scaffold changed, therefore, the attendance of NPs caused a decreasing porosity, decreased swelling, and low rate of degradation. The release profile results showed that the NPs-loaded CHS/Gel scaffolds were able to simultaneously release ALN and Ca ions due to the decomposition of NPs. Additionally, the loading of NPs in the CHS/Gel scaffold led to an increment in alkaline phosphatase (ALP) activity and the quantity of deposited Ca along with osteogenesis gene markers. These findings suggest that the NPs-loaded CHS/Gel scaffold has the potential to enhance the differentiation of human adipose tissue-derived mesenchymal stem cells, making it a promising approach for bone repair.

Chitosan-based promising scaffolds for the construction of tailored nanosystems against osteoporosis: Current status and future prospects

Despite advancements in therapeutic techniques, restoring bone tissue after damage remains a challenging task. Tissue engineering or targeted drug delivery solutions aim to meet the pressing clinical demand for treatment alternatives by creating substitute materials that imitate the structural and biological characteristics of healthy tissue. Polymers derived from natural sources typically exhibit enhanced biological compatibility and bioactivity when compared to manufactured polymers. Chitosan is a unique polysaccharide derived from chitin through deacetylation, offering biodegradability, biocompatibility, and antibacterial activity. Its cationic charge sets it apart from other polymers, making it a valuable resource for various applications. Modifications such as thiolation, alkylation, acetylation, or hydrophilic group incorporation can enhance chitosan's swelling behavior, cross-linking, adhesion, permeation, controllable drug release, enzyme inhibition, and antioxidative properties. Chitosan scaffolds possess considerable potential for utilization in several biological applications. An intriguing application is its use in the areas of drug distribution and bone tissue engineering. Due to their excellent biocompatibility and lack of toxicity, they are an optimal material for this particular usage. This article provides a comprehensive analysis of osteoporosis, including its pathophysiology, current treatment options, the utilization of natural polymers in disease management, and the potential use of chitosan scaffolds for drug delivery systems aimed at treating the condition.

Modified-Hydroxyapatite-Chitosan Hybrid Composite Interfacial Coating on 3D Polymeric Scaffolds for Bone Tissue Engineering

Three dimensional (3D) scaffolds have huge limitations due to their low porosity, mechanical strength, and lack of direct cell-bioactive drug contact. Whereas bisphosphonate drug has the ability to stimulate osteogenesis in osteoblasts and bone marrow mesenchymal stem cells (hMSC) which attracted its therapeutic use. However it is hard administration low bioavailability, and lack of site-specificity, limiting its usage. The proposed scaffold architecture allows cells to access the bioactive surface at their apex by interacting at the scaffold's interfacial layer. The interface of 3D polycaprolactone (PCL) scaffolds has been coated with alendronate-modified hydroxyapatite (MALD) enclosed in a chitosan matrix, to mimic the native environment and stupulate the through interaction of cells to bioactive layer. Where the mechanical strength will be provided by the skeleton of PCL. In the MALD composite's hydroxyapatite (HAP) component will govern alendronate (ALD) release behavior, and HAP presence will drive the increase in local calcium ion concentration increases hMSC proliferation and differentiation. In results, MALD show release of 86.28 ± 0.22. XPS and SEM investigation of the scaffold structure, shows inspiring particle deposition with chitosan over the interface. All scaffolds enhanced cell adhesion, proliferation, and osteocyte differentiation for over a week without in vitro cell toxicity with 3.03 ± 0.2 kPa mechanical strength.

Current application and modification strategy of marine polysaccharides in tissue regeneration: A review

Marine polysaccharides (MPs) are exceptional bioactive materials that possess unique biochemical mechanisms and pharmacological stability, making them ideal for various tissue engineering applications. Certain MPs, including agarose, alginate, carrageenan, chitosan, and glucan have been successfully employed as biological scaffolds in animal studies. As carriers of signaling molecules, scaffolds can enhance the adhesion, growth, and differentiation of somatic cells, thereby significantly improving the tissue regeneration process. However, the biological benefits of pure MPs composite scaffold are limited. Therefore, physical, chemical, enzyme modification and other methods are employed to expand its efficacy. Chemically, the structural properties of MPs scaffolds can be altered through modifications to functional groups or molecular weight reduction, thereby enhancing their biological activities. Physically, MPs hydrogels and sponges emulate the natural extracellular matrix, creating a more conducive environment for tissue repair. The porosity and high permeability of MPs membranes and nanomaterials expedite wound healing. This review explores the distinctive properties and applications of select MPs in tissue regeneration, highlighting their structural versatility and biological applicability. Additionally, we provide a brief overview of common modification strategies employed for MP scaffolds. In conclusion, MPs have significant potential and are expected to be a novel regenerative material for tissue engineering.

Dual-crosslinked in-situ forming alginate/silk fibroin hydrogel with potential for bone tissue engineering

This study aimed to improve the mechanical and biological properties of alginate-based hydrogels. For this purpose, in-situ forming hydrogels were prepared by dual crosslinking of Alginate (Alg)/Oxidized Alginate (OAlg)/Silk Fibroin (SF) through simultaneous ionic gelation using CaCO3-GDL and Schiff-base reaction. The resulting hydrogels were characterized by FTIR, SEM, compressive modulus, and rheological tests. Compared to the physically-crosslinked alginate hydrogel, the compressive modulus of dual-crosslinked Alg/OAlg/SF hydrogel increased from 28 to 67 kPa, due to the covalent imine bond formation. Then, MTT and DAPI staining assays were performed to demonstrate the biocompatibility of hydrogel. Furthermore, the differentiation potential of bone marrow mesenchymal stem cells encapsulated in hydrogel scaffolds to bone tissue was tested by ALP activity, Alizarin Red staining, and real-time PCR. The overall results showed the potential of Alginate/Oxidized Alginate/Silk Fibroin hydrogel scaffold for bone tissue engineering applications.

Biomaterials combined with ADSCs for bone tissue engineering: current advances and applications

In recent decades, bone tissue engineering, which is supported by scaffold, seed cells and bioactive molecules (BMs), has provided new hope and direction for treating bone defects. In terms of seed cells, compared to bone marrow mesenchymal stem cells, which were widely utilized in previous years, adipose-derived stem cells (ADSCs) are becoming increasingly favored by researchers due to their abundant sources, easy availability and multi-differentiation potentials. However, there is no systematic theoretical basis for selecting appropriate biomaterials loaded with ADSCs. In this review, the regulatory effects of various biomaterials on the behavior of ADSCs are summarized from four perspectives, including biocompatibility, inflammation regulation, angiogenesis and osteogenesis, to illustrate the potential of combining various materials with ADSCs for the treatment of bone defects. In addition, we conclude the influence of additional application of various BMs on the bone repair effect of ADSCs, in order to provide more evidences and support for the selection or preparation of suitable biomaterials and BMs to work with ADSCs. More importantly, the associated clinical case reports and experiments are generalized to provide additional ideas for the clinical transformation and application of bone tissue engineering loaded with ADSCs.

Advances in materials-based therapeutic strategies against osteoporosis

Osteoporosis is caused by the disruption in homeostasis between bone formation and bone resorption. Conventional management of osteoporosis involves systematic drug administration and hormonal therapy. These treatment strategies have limited curative efficacy and multiple adverse effects. Biomaterials-based therapeutic strategies have recently emerged as promising alternatives for the treatment of osteoporosis. The present review summarizes the current status of biomaterials designed for managing osteoporosis. The advantages of biomaterials-based strategies over conventional systematic drug treatment are presented. Different anti-osteoporotic delivery systems are concisely addressed. These materials include injectable hydrogels and nanoparticles, as well as anti-osteoporotic bone tissue engineering materials. Fabrication techniques such as 3D printing, electrostatic spinning and artificial intelligence are appraised in the context of how the use of these adjunctive techniques may improve treatment efficacy. The limitations of existing biomaterials are critically analyzed, together with deliberation of the future directions in biomaterials-based therapies. The latter include discussion on the use of combination strategies to enhance therapeutic efficacy in the osteoporosis niche.

Osteoimmunomodulatory Nanoparticles for Bone Regeneration

Treatment of large bone fractures remains a challenge for orthopedists. Bone regeneration is a complex process that includes skeletal cells such as osteoblasts, osteoclasts, and immune cells to regulate bone formation and resorption. Osteoimmunology, studying this complicated process, has recently been used to develop biomaterials for advanced bone regeneration. Ideally, a biomaterial shall enable a timely switch from early stage inflammatory (to recruit osteogenic progenitor cells) to later-stage anti-inflammatory (to promote differentiation and terminal osteogenic mineralization and model the microstructure of bone tissue) in immune cells, especially the M1-to-M2 phenotype switch in macrophage populations, for bone regeneration. Nanoparticle (NP)-based advanced drug delivery systems can enable the controlled release of therapeutic reagents and the delivery of therapeutics into specific cell types, thereby benefiting bone regeneration through osteoimmunomodulation. In this review, we briefly describe the significance of osteoimmunology in bone regeneration, the advancement of NP-based approaches for bone regeneration, and the application of NPs in macrophage-targeting drug delivery for advanced osteoimmunomodulation.

How Efficient are Alendronate-Nano/Biomaterial Combinations for Anti-Osteoporosis Therapy? An Evidence-Based Review of the Literature

Osteoporosis is defined as a systemic skeletal disease characterized by low bone mass and microarchitectural deterioration of bone tissue, with a consequent increase in bone fragility and susceptibility to fracture. Because of the systemic nature of osteoporosis, the associated escalation in fracture risk affects virtually all skeletal sites. The problem is serious since it is estimated that more than 23 million men and women are at high risk of osteoporotic-like breakages in the European Union. Alendronate (ALN) is the most commonly prescribed oral nitrogen-containing bisphosphonate (BP) for the prevention and the therapy of osteoporosis. This is also one of the most intensely studied drugs in this field. However, ALN is characterized by restricted oral absorption and bioavailability and simultaneously its administration has serious side-effects (jaw osteonecrosis, irritation of the gastrointestinal system, nausea, musculoskeletal pain, and cardiovascular risks). Therefore, delivery systems enabling controlled release and local action of this drug are of great interest, being widely researched and presented in the literature. In this review, we discuss the current trends in the design of various types of alendronate carriers. Our paper is focused on the most recent developments in the field of nano/biomaterials-based systems for ALN delivery, including nano/microformulations, synthetic/natural polymeric and inorganic materials, hydrogel-based materials, scaffolds, coated-like structures, as well as organic-inorganic hybrids. Topics related to the treatment of complex bone diseases including osteoporosis have been covered in several more general reviews; however, the systems for this particular drug have not yet been discussed in detail.

Intelligent control of nanoparticle synthesis on microfluidic chips with machine learning

Nanoparticles play irreplaceable roles in optoelectronic sensing, medical therapy, material science, and chemistry due to their unique properties. There are many synthetic pathways used for the preparation of nanoparticles, and different synthetic pathways can produce nanoparticles with different properties. Therefore, it is crucial to control the properties of nanoparticles precisely to impart the desired functions. In general, the properties of nanoparticles are influenced by their sizes and morphologies. Current technology for the preparation of nanoparticles on microfluidic chips requires repeated experimental debugging and significant resources to synthesize nanoparticles with precisely the desired properties. Machine learning-assisted synthesis of nanoparticles is a sensible choice for addressing this challenge. In this paper, we review many recent studies on syntheses of nanoparticles assisted by machine learning. Moreover, we describe the working steps of machine learning, the main algorithms, and the main ways to obtain datasets. Finally, we discuss the current problems of this research and provide an outlook.

Role of Polymers in Microfluidic Devices

Polymers are sustainable and renewable materials that are in high demand due to their excellent properties. Natural and synthetic polymers with high flexibility, good biocompatibility, good degradation rate, and stiffness are widely used for various applications, such as tissue engineering, drug delivery, and microfluidic chip fabrication. Indeed, recent advances in microfluidic technology allow the fabrication of polymeric matrix to construct microfluidic scaffolds for tissue engineering and to set up a well-controlled microenvironment for manipulating fluids and particles. In this review, polymers as materials for the fabrication of microfluidic chips have been highlighted. Successful models exploiting polymers in microfluidic devices to generate uniform particles as drug vehicles or artificial cells have been also discussed. Additionally, using polymers as bioink for 3D printing or as a matrix to functionalize the sensing surface in microfluidic devices has also been mentioned. The rapid progress made in the combination of polymers and microfluidics presents a low-cost, reproducible, and scalable approach for a promising future in the manufacturing of biomimetic scaffolds for tissue engineering.

Microfluidic Nanoparticles for Drug Delivery

Nanoparticles (NPs) have attracted tremendous interest in drug delivery in the past decades. Microfluidics offers a promising strategy for making NPs for drug delivery due to its capability in precisely controlling NP properties. The recent success of mRNA vaccines using microfluidics represents a big milestone for microfluidic NPs for pharmaceutical applications, and its rapid scaling up demonstrates the feasibility of using microfluidics for industrial-scale manufacturing. This article provides a critical review of recent progress in microfluidic NPs for drug delivery. First, the synthesis of organic NPs using microfluidics focusing on typical microfluidic methods and their applications in making popular and clinically relevant NPs, such as liposomes, lipid NPs, and polymer NPs, as well as their synthesis mechanisms are summarized. Then, the microfluidic synthesis of several representative inorganic NPs (e.g., silica, metal, metal oxide, and quantum dots), and hybrid NPs is discussed. Lastly, the applications of microfluidic NPs for various drug delivery applications are presented.

Merits and advances of microfluidics in the pharmaceutical field: design technologies and future prospects

Microfluidics is used to manipulate fluid flow in micro-channels to fabricate drug delivery vesicles in a uniform tunable size. Thanks to their designs, microfluidic technology provides an alternative and versatile platform over traditional formulation methods of nanoparticles. Understanding the factors that affect the formulation of nanoparticles can guide the proper selection of microfluidic design and the operating parameters aiming at producing nanoparticles with reproducible properties. This review introduces the microfluidic systems' continuous flow (single-phase) and segmented flow (multiphase) and their different mixing parameters and mechanisms. Furthermore, microfluidic approaches for efficient production of nanoparticles as surface modification, anti-fouling, and post-microfluidic treatment are summarized. The review sheds light on the used microfluidic systems and operation parameters applied to prepare and fine-tune nanoparticles like lipid, poly(lactic-co-glycolic acid) (PLGA)-based nanoparticles as well as cross-linked nanoparticles. The approaches for scale-up production using microfluidics for clinical or industrial use are also highlighted. Furthermore, the use of microfluidics in preparing novel micro/nanofluidic drug delivery systems is presented. In conclusion, the characteristic vital features of microfluidics offer the ability to develop precise and efficient drug delivery nanoparticles.

Alendronate crosslinked chitosan/polycaprolactone scaffold for bone defects repairing

Here, we evaluated osteogenic differentiation in vitro and new bone formation in vivo using an alendronate-loaded chitosan/polycaprolactone scaffold (CS/PCL) in rats with a critical-sized calvarial defect. Through the action of genipin, which has a crosslinking function, alendronate (AL) was anchored throughout the CS/PCL composite scaffold (CS/PCL@AL) to form an AL sustained release system. We demonstrated that CS/PCL@AL scaffolds significantly enhanced the osteogenic differentiation of ectomesenchymal stem cells (EMSCs) in vitro. Additionally, we explored the possible molecular mechanism of CS/PCL@AL scaffolds in the osteogenic differentiation of EMSCs. This composite scaffold exerted two positive effects on EMSC osteogenic differentiation: 1) the CS/PCL@AL scaffold enhanced EMSC osteogenic differentiation by upregulating bone morphogenetic protein 2, interleukin 10 and laminin expression; and 2) the CS/PCL@AL scaffold promoted the osteogenic differentiation of EMSCs by activating the yes-associated protein (YAP) signaling pathway. YAP and its downstream target transglutaminase are crucial mediators in the osteogenic differentiation of EMSCs. Finally, micro-computed tomography analyses and histology results suggested that the CS/PCL@AL scaffold exhibited a superior capacity to accelerate new and mature bone formation in skull bone defects in Sprague-Dawley rats. This simple and low-cost technology may represent a promising strategy to construct an efficient delivery system to repair bone defects.

Recent advances of chitosan-based nanoparticles for biomedical and biotechnological applications

Chitosan is a natural alkaline polysaccharide, which widely exists in marine crustaceans such as shrimp and crab, has been shown to have various biological activities. It has attracted considerable attention in biomedicine and nanomaterials fields because of its excellent properties, such as biocompatibility, biodegradability, non-toxicity and easy access. In addition, because of active hydroxyl and amino groups in chitosan molecules, different functional groups can be introduced into chitosan molecules by molecular modification or chemical modification, which extends their applications. Nanoparticles with small size and large surface area can be used as diagnostic and therapeutic tools in the biomedical field, which make it easier to understand, detect and treat human diseases. The nanomaterials based on chitosan have important applications in biomedicine, industry, pharmacy, agriculture, and other fields. This review highlights the recent advances on chitosan-based nanoparticles for antibacterial property, drug and gene delivery, cancer and hyperthermia therapy, cell imaging, restorative dentistry, wound healing, tissue engineering and other biomedical fields. The nanotechnology fields involving biosensors, water treatment, food industry and agriculture are also briefly reviewed.

Chitin and chitosan on the nanoscale

In a matter of decades, nanomaterials from biomass, exemplified by nanocellulose, have rapidly transitioned from once being a subject of curiosity to an area of fervent research and development, now reaching the stages of commercialization and industrial relevance. Nanoscale chitin and chitosan, on the other hand, have only recently begun to raise interest. Attractive features such as excellent biocompatibility, antibacterial activity, immunogenicity, as well as the tuneable handles of their acetylamide (chitin) or primary amino (chitosan) functionalities indeed display promise in areas such as biomedical devices, catalysis, therapeutics, and more. Herein, we review recent progress in the fabrication and development of these bio-nanomaterials, describe in detail their properties, and discuss the initial successes in their applications. Comparisons are made to the dominant nanocelluose to highlight some of the inherent advantages that nanochitin and nanochitosan may possess in similar application.

Advanced Materials Based on Nanosized Hydroxyapatite

The development of new materials based on hydroxyapatite has undergone a great evolution in recent decades due to technological advances and development of computational techniques. The focus of this review is the various attempts to improve new hydroxyapatite-based materials. First, we comment on the most used processing routes, highlighting their advantages and disadvantages. We will now focus on other routes, less common due to their specificity and/or recent development. We also include a block dedicated to the impact of computational techniques in the development of these new systems, including: QSAR, DFT, Finite Elements of Machine Learning. In the following part we focus on the most innovative applications of these materials, ranging from medicine to new disciplines such as catalysis, environment, filtration, or energy. The review concludes with an outlook for possible new research directions.

Strategies to load therapeutics into polysaccharide-based nanogels with a focus on microfluidics: A review

Nowadays nanoparticles are increasingly investigated for the targeted and controlled delivery of therapeutics, as suggested by the high number of research articles (2400 in 2000 vs 8500 in 2020). Among them, almost 2% investigated nanogels in 2020. Nanogels or nanohydrogels (NGs) are nanoparticles formed by a swollen three-dimensional network of synthetic polymers or natural macromolecules such as polysaccharides. NGs represent a highly versatile nanocarrier, able to deliver a number of therapeutics. Currently, NGs are undergoing clinical trials for the delivery of anti-cancer vaccines. Herein, the strategies to load low molecular weight drugs, (poly)peptides and genetic material into polysaccharide NGs as well as to formulate NGs-based vaccines are summarized, with a focus on the microfluidics approach.

Recent advances in microfluidic-aided chitosan-based multifunctional materials for biomedical applications

Chitosan-based biomaterials has shown great advantages in a broad range of applications, including drug delivery, clinical diagnosis, cell culture and tissue engineering. However, due to the lack of control over the fabrication processes by conventional techniques, the wide application of chitosan-based biomaterials has been hampered. Recently, microfluidics has been demonstrated as one of the most promising platforms to fabricate high-performance chitosan-based multifunctional materials with monodisperse size distribution and accurately controlled morphology and microstructures, which show great promising for biomedical applications. Here, we review recent progress of the fabrication of chitosan-based biomaterials with different structures and integrated functions by microfluidic technology. A comprehensive and in-depth depiction of critical microfluidic formation mechanism and process of various chitosan-based materials are first interpreted, with particular descriptions about the microfluidic-mediated control over the morphology and microstructures. Afterwards, recently emerging representative applications of chitosan-based multifunctional materials in various fields, are systematically summarized. Finally, the conclusions and perspectives on further advancing the microfluidic-aided chitosan-based multifunctional materials toward potential and versatile development for fundamental researches and biomedicine are proposed.

Nanotechnology in ovarian cancer: Diagnosis and treatment

To overcome the drawbacks of conventional delivery, this review spotlights a number of nanoscale drug delivery systems, including nanoparticles, liposomes, nano micelles, branched dendrimers, nanocapsules, and nanostructured lipid formulations for the targeted therapy of ovarian cancer. These nanoformulations offer numerous advantages to promote therapeutic drug delivery such as nontoxicity, biocompatibility, good biodegradability, increased therapeutic impact than free drugs, and non-inflammatory effects. Importantly, the development of specific ligands functionalized nanoformulations enable preferential targeting of ovarian tumors and eventually amplify the therapeutic potential compared to nonfunctionalized counterparts. Ovarian cancer is typically identified by biomarker assessment such as CA125, HE4, Mucin 1, and prostatic. There is, nevertheless, a tremendous demand for less costly, faster, and compact medical tools, both for timely detection and ovarian cancer control. This paper explored multiple types of tumor marker-based on nanomaterial biosensors. Initially, we mention different forms of ovarian cancer biomarkers involving CA125, human epididymis protein 4 (HE4), mucin 1 (MUC1), and prostate. It is accompanied by a brief description of new nanotechnology methods for diagnosis. Nanobiosensors for evaluating ovarian cancer biomarkers can be categorized based on electrochemical, optical, paper-based, giant magnetoresistive, and lab-on-a-chip devices.

Guided bone regeneration by the development of alendronate sodium loaded in-situ gel and membrane formulations

Biocompatible materials applied in guided bone regeneration are needed to prevent leakage caused by the invasion of peripheral epithelium. (2.1) The aim of this study is to develop a thermosensitive in situ gel system containing alendronate sodium loaded PLGA nanoparticles and alendronate sodium loaded membranes for guided bone regeneration. Thermosensitive Pluronic F127 gel system was preferred to prevent soft tissue migration to the defect site and prolong the residence time of the nanoparticles in this region. In situ gel system was combined with membrane formulation to enhance bone regenaration activity. Efficacy of combination system was investigated by implanting in 0.5 × 0.5 cm critical size defect in tibia of New Zealand female rabbits. According to the histopathological results, fibroblast formations were found at defect area after 6 weeks of post implantation. In contrast, treatment with the combination of in-situ gel containing nanoparticles with membrane provided woven bone formation with mature bone after 4 weeks of post implantation. As a results, the combination of in-situ gel formulation containing alendronate sodium-loaded nanoparticles with membrane formulation could be effectively applided for guided bone regeneration.