E-jet 3D printed drug delivery implants to inhibit growth and metastasis of orthotopic breast cancer

Local Delivery of Dual Stem Cell-Derived Exosomes Using an Electrospun Nanofibrous Platform for the Treatment of Traumatic Brain Injury

Traumatic brain injury poses serious physical, psychosocial, and economic threats. Although systemic administration of stem cell-derived exosomes has recently been proven to be a promising modality for traumatic brain injury treatment, they come with distinct drawbacks. Luckily, various biomaterials have been developed to assist local delivery of exosomes to improve the targeting of organs, minimize nonspecific accumulation in vital organs, and ensure the protection and release of exosomes. In this study, we developed an electrospun nanofibrous scaffold to provide sustained delivery of dual exosomes derived from mesenchymal stem cells and neural stem cells for traumatic brain injury treatment. The electrospun nanofibrous scaffold employed a functionalized layer of polydopamine on electrospun poly(ε-caprolactone) nanofibers, thereby enhancing the efficient incorporation of exosomes through a synergistic interplay of adhesive forces, hydrogen bonding, and electrostatic interactions. First, the mesenchymal stem cell-derived exosomes and the neural stem cell-derived exosomes were found to modulate microglial polarization toward M2 phenotype, play an important role in the modulation of inflammatory responses, and augment axonal outgrowth and neural repair in PC12 cells. Second, the nanofibrous scaffold loaded with dual stem cell-derived exosomes (Duo-Exo@NF) accelerated functional recovery in a murine traumatic brain injury model, as it mitigated the presence of reactive astrocytes and microglia while elevating the levels of growth associated protein-43 and doublecortin. Additionally, multiomics analysis provided mechanistic insights into how dual stem cell-derived exosomes exerted its therapeutic effects. These findings collectively suggest that our novel Duo-Exo@NF system could function as an effective treatment modality for traumatic brain injury using sustained local delivery of dual exosomes from stem cells.

Recent Progress in Implantable Drug Delivery Systems

In recent years, tremendous effort is devoted to developing platforms, such as implantable drug delivery systems (IDDSs), with temporally and spatially controlled drug release capabilities and improved adherence. IDDSs have multiple advantages: i) the timing and location of drug delivery can be controlled by patients using specific stimuli (light, sound, electricity, magnetism, etc.). Some intelligent "closed-loop" IDDS can even realize self-management without human participation. ii) IDDSs enable continuous and stable delivery of drugs over a long period (months to years) and iii) to administer drugs directly to the lesion, thereby helping reduce dosage and side effects. iv) IDDSs enable personalized drug delivery according to patient needs. The high demand for such systems has prompted scientists to make efforts to develop intelligent IDDS. In this review, several common stimulus-responsive mechanisms including endogenous (e.g., pH, reactive oxygen species, proteins, etc.) and exogenous stimuli (e.g., light, sound, electricity, magnetism, etc.), are given in detail. Besides, several types of IDDS reported in recent years are reviewed, including various stimulus-responsive systems based on the above mechanisms, radio frequency-controlled IDDS, "closed-loop" IDDS, self-powered IDDS, etc. Finally, the advantages and disadvantages of various IDDS, bottleneck problems, and possible solutions are analyzed to provide directions for subsequent research.

Implantable, 3D-Printed Alginate Scaffolds with Bismuth Sulfide Nanoparticles for the Treatment of Local Breast Cancer via Enhanced Radiotherapy

Surgical removal of tumor tissue remains the primary clinical approach for addressing breast cancer; however, complete tumor excision is challenging, and the remaining tumor cells can lead to tumor recurrence and metastasis over time, which substantially deteriorates the life quality of the patients. With the aim to improve local cancer radiotherapy, this work reports the fabrication of alginate (Alg) scaffolds containing bovine serum albumin (BSA)-coated bismuth sulfide (Bi2S3@BSA) nanoradiosensitizers using three-dimensional (3D) printing. Under single-dose X-ray irradiation in vitro, Alg-Bi2S3@BSA scaffolds significantly increase the formation of reactive oxygen species, enhance the inhibition of breast cancer cells, and suppress their colony formation capacity. In addition, scaffolds implanted under tumor tissue in murine model show high therapeutic efficacy by reducing the tumor volume growth rate under single-dose X-ray irradiation, while histological observation of main organs reveals no cytotoxicity or side effects. 3D-printed Alg-Bi2S3@BSA scaffolds produced with biocompatible and biodegradable materials may potentially lower the recurrence and metastasis rates in breast cancer patients by inhibiting residual tumor cells following postsurgery as well as exhibit anticancer properties in other solid tumors.

Development and characterization of 3D printed ethylene vinyl acetate (EVA) as drug delivery device for the treatment of overactive bladder

The overactive bladder is a condition characterized by a sudden urge to urinate, even with small volumes of urine present in the bladder. The current treatments available for this pathology consist on conservative approaches and the continuous administration of drugs, which when made by conventional methods has limitations related to the first pass metabolism, bioavailability, severe side effects, and low patient adherence to treatments, ultimately leading to low effectiveness. Within this context, the present work proposes the design, manufacture, and characterization of an intravesical implant for the treatment of overactive bladder pathology, using EVA copolymer as a matrix and oxybutynin as a drug. The fabrication of devices through two manufacturing techniques (extrusion and additive manufacturing by fused filament fabrication, FFF) and the evaluation of the implants through characterization tests was proposed. The usability and functionality were evaluated through simulated insertion of the device/prototype in a bladder model through catheter insertion tests. The safety and effectiveness of the devices was investigated from mechanical testing as well as drug release assays. Drug release assays presented a burst release in the first 24 h, followed by a release of 1.8 and 2.8 mg/d, totalizing 32 d. Mechanical tests demonstrated an increase in the stiffness of the specimens due to the addition of the drug, showing a change in maximum stress and strain at break. The released dose was higher than that usually presented when considering the oral administration route, showing the optimization of the development of this implant has the potential to improve the quality of life of patients with overactive bladder.

Printing a cure: A tailored solution for localized drug delivery in liver cancer treatment

Adjuvant chemotherapy is highly recommended for liver cancer to enhance survival rates due to its tendency to recur frequently. Localized drug-eluting implants have gained traction as an alternative to overcome the limitations of systemic chemotherapy. This work describes the development of biodegradable 3D printed (3DP) bilayer films loaded with 5-fluorouracil (5FU) and cisplatin (Cis) with different infill percentages where the 5FU layers were 40%, 30%, and 30% and Cis layers were 10%, 15%, and 10% for films A, B, and C, respectively. The relevant characterization tests were performed, and the drug content of films was 0.68, 0.50, and 0.50 mg of 5FU and 0.39, 0.80, and 0.34 mg of Cis for films A, B, and C, respectively. Cis release was affected by the alterations to the film design, where films A, B, and C showed complete release at 12, 14, and 23 days, respectively. However, 5FU was released over 24 h for all films. The films were stable for up to two weeks after storage at 25 °C/65% relative humidity and four weeks at 4 °C where drug content, tensile strength, FTIR, and thermal analysis results demonstrated negligible alterations. The cytotoxicity of the films was assessed by MTS assays using HepG2 cell lines demonstrating up to 81% reduction in cell viability compared to blank films. Moreover, apoptosis was confirmed by Western Blots and the determination of mitochondrial cell potential, highlighting the potential of these films as a promising approach in adjuvant chemotherapy.

3D printing in pediatric surgery

Pediatric surgery presents a unique challenge, requiring a specialized approach due to the intricacies of compact anatomy and the presence of distinct congenital features in young patients. Surgeons are tasked with making decisions that not only address immediate concerns but also consider the evolving needs of children as they grow. The advent of three-dimensional (3D) printing has emerged as a valuable tool to facilitate a personalized medical approach. This paper starts by outlining the basics of 3D modeling and printing. We then delve into the transformative role of 3D printing in pediatric surgery, elucidating its applications, benefits, and challenges. The paper concludes by envisioning the future prospects of 3D printing, foreseeing advancements in personalized treatment approaches, improved patient outcomes, and the continued evolution of this technology as an indispensable asset in the pediatric surgical arena.

Caffeic acid-grafted chitosan/sodium alginate/nanoclay-based multifunctional 3D-printed hybrid scaffolds for local drug release therapy after breast cancer surgery

Breast cancer is one of the most common malignant tumors in women all over the world. Mastectomy is the most effective treatment, but there are serious problems such as high tumor recurrence rate and side effects of chemotherapy. Therefore, there is an urgent need for a therapeutic strategy that can effectively promote postoperative wound healing and inhibit local tumor recurrence. In this study, a 3D printing scaffold based on carbon dots-curcumin nano-drug release (CCNPs) was developed as a local drug delivery platform (named CCNACA using CCNPs, Sodium alginate, Nanoclay and Caffeic Acid grafted Chitosan as raw materials), which has the ability to visualize drug release. The 14-day drug release test in vitro showed that the tumor inhibition rate of CCNACA scaffolds on breast cancer cells (MCF-7) was 73.77 ± 1.68 %. And the CCNACA scaffolds had good long-term antibacterial (Escherichia coli and Staphylococcus aureus) activity. Animal experiments have shown that implanting CCNACA scaffolds into surgical defects can inhibit postoperative residual cancer cells, reduce inflammation, promote angiogenesis, and repair tissue defects caused by surgery. In summary, the local drug delivery system of this manuscript has great potential in wound healing and prevention of tumor recurrence after breast cancer surgery.

Three-Dimensional Printing as a Progressive Innovative Tool for Customized and Precise Drug Delivery

While using three-dimensional printing, materials are deposited layer by layer in accordance with the digital model created by computer-aided design software. Numerous research teams have shown interest in this technology throughout the last few decades to produce various dosage forms in the pharmaceutical industry. The number of publications has increased since the first printed medicine was approved in 2015 by Food and Drug Administration. Considering this, the idea of creating complex, custom-made structures that are loaded with pharmaceuticals for tissue engineering and dose optimization is particularly intriguing. New approaches and techniques for creating unique medication delivery systems are made possible by the development of additive manufacturing keeping in mind the comparative advantages it has over conventional methods of manufacturing medicaments. This review focuses on three-dimensional printed formulations grouped in orally disintegrated tablets, buccal films, implants, suppositories, and microneedles. The various types of techniques that are involved in it are summarized. Additionally, challenges and applications related to three-dimensional printing of pharmaceuticals are also being discussed.

Application of 3D printing technology in tumor diagnosis and treatment

3D printing technology is an increasing approach consisting of material manufacturing through the selective incremental delamination of materials to form a 3D structure to produce products. This technology has different advantages, including low cost, short time, diversification, and high precision. Widely adopted additive manufacturing technologies enable the creation of diagnostic tools and expand treatment options. Coupled with its rapid deployment, 3D printing is endowed with high customizability that enables users to build prototypes in shorts amounts of time which translates into faster adoption in the medical field. This review mainly summarizes the application of 3D printing technology in the diagnosis and treatment of cancer, including the challenges and the prospects combined with other technologies applied to the medical field.

Reverse Engineering and 3D Printing of Medical Devices for Drug Delivery and Drug-Embedded Anatomic Implants

In recent years, 3D printing (3DP) has advanced traditional medical treatments. This review explores the fusion of reverse engineering and 3D printing of medical implants, with a specific focus on drug delivery applications. The potential for 3D printing technology to create patient-specific implants and intricate anatomical models is discussed, along with its ability to address challenges in medical treatment. The article summarizes the current landscape, challenges, benefits, and emerging trends of using 3D-printed formulations for medical implantation and drug delivery purposes.

High-Precision 3D Printing of Microporous Cochlear Implants for Personalized Local Drug Delivery

Hearing loss is a highly prevalent multifactorial disorder affecting 20% of the global population. Current treatments using the systemic administration of drugs are therapeutically ineffective due to the anatomy of the cochlea and the existing blood-labyrinth barrier. Local drug delivery systems can ensure therapeutic drug concentrations locally while preventing adverse effects caused by high dosages of systemically administered drugs. Here, we aimed to design, fabricate, and characterize a local drug delivery system for the human cochlea. The design was relevant to the size of the human ear, included two different shapes, and incorporated two different microporous structures acting as reservoirs for drug loading and release. The four cochlear implant designs were printed using the two-photon polymerization (2PP) technique and the IP-Q photoresist. The optimized 2PP process enabled the fabrication of the cochlear implants with great reproducibility and shape fidelity. Rectangular and cylindrical implants featuring cylindrical and tapered tips, respectively, were successfully printed. Their outer dimensions were 0.6 × 0.6 × 2.4 mm3 (L × W × H). They incorporated internal porous networks that were printed with high accuracy, yielding pore sizes of 17.88 ± 0.95 μm and 58.15 ± 1.62 μm for the designed values of 20 μm and 60 μm, respectively. The average surface roughness was 1.67 ± 0.24 μm, and the water contact angle was 72.3 ± 3.0°. A high degree of polymerization (~90%) of the IP-Q was identified after printing, and the printed material was cytocompatible with murine macrophages. The cochlear implants designed and 3D printed in this study, featuring relevant sizes for the human ear and tunable internal microporosity, represent a novel approach for personalized treatment of hearing loss through local drug delivery.

Customizable 3D Printed Implants Containing Triamcinolone Acetonide: Development, Analysis, Modification, and Modeling of Drug Release

Three-dimensional-printed customizable drug-loaded implants provide promising opportunities to improve the current therapy options. In this study, we present a modular implant in which shape, dosage, and drug release can be individualized independently of each other to patient characteristics to improve parenteral therapy with triamcinolone acetonide (TA) over three months. This study focused on the examination of release modification via fused deposition modeling and subsequent prediction. The filaments for printing consisted of TA, ethyl cellulose, hypromellose, and triethyl citrate. Two-compartment implants were successfully developed, consisting of a shape-adaptable shell and an embedded drug-loaded network. For the network, different strand widths and pore size combinations were printed and analyzed in long-term dissolution studies to evaluate their impact on the release performance. TA release varied between 8.58 ± 1.38 mg and 21.93 mg ± 1.31 mg over three months depending on the network structure and the resulting specific surface area. Two different approaches were employed to predict the TA release over time. Because of the varying release characteristics, applicability was limited, but successful in several cases. Using a simple Higuchi-based approach, good release predictions could be made for a release time of 90 days from the release data of the initial 15 days (RMSEP ≤ 3.15%), reducing the analytical effort and simplifying quality control. These findings are important to establish customizable implants and to optimize the therapy with TA for specific intra-articular diseases.

Solid implantable devices for sustained drug delivery

Implantable drug delivery systems (IDDS) are an attractive alternative to conventional drug administration routes. Oral and injectable drug administration are the most common routes for drug delivery providing peaks of drug concentrations in blood after administration followed by concentration decay after a few hours. Therefore, constant drug administration is required to keep drug levels within the therapeutic window of the drug. Moreover, oral drug delivery presents alternative challenges due to drug degradation within the gastrointestinal tract or first pass metabolism. IDDS can be used to provide sustained drug delivery for prolonged periods of time. The use of this type of systems is especially interesting for the treatment of chronic conditions where patient adherence to conventional treatments can be challenging. These systems are normally used for systemic drug delivery. However, IDDS can be used for localised administration to maximise the amount of drug delivered within the active site while reducing systemic exposure. This review will cover current applications of IDDS focusing on the materials used to prepare this type of systems and the main therapeutic areas of application.

3D printed implantable drug delivery devices for women's health: Formulation challenges and regulatory perspective

Modern pharmaceutical interventions are shifting from traditional "one-size-fits-all" approaches toward tailored therapies. Following the regulatory approval of Spritam®, the first marketed drug manufactured using three-dimensional printing (3DP) technologies, there is a precedence set for the use of 3DP in the manufacture of pharmaceutical products. The involvement of 3DP technologies in pharmaceutical research has demonstrated its capabilities in enabling the customisation of characteristics such as drug dosing, release characteristics and product designs on an individualised basis. Nonetheless, research into 3DP implantable drug delivery devices lags behind that for oral devices, cell-based therapies and tissue engineering applications. The recent efforts and initiatives to address the disparity in women's health is overdue but should provide a drive for more research into this area, especially using new and emerging technologies as 3DP. Therefore, the focus of this review has been placed on the unique opportunity of formulating personalised implantable drug delivery systems using 3DP for women's health applications, particularly passive implants. An evaluation of the current landscape and key formulation challenges for achieving this is provided supplemented with critical insight into the current global regulatory status and its outlook.

Development of Injectable and Biodegradable Needle-Type Starch Implant for Effective Intratumoral Drug Delivery and Distribution

Introduction

Compared to intravenous administration, intratumoral drug administration enables the direct delivery of drugs to tumors and mitigates the systemic absorption of drugs and associated drug-induced side effects. However, intratumoral drug administration presents several challenges. The high interstitial fluid pressure (IFP) of the tumor prevents the retention of drugs within the tumor; thus, significant amounts of the drugs are absorbed systemically through the bloodstream or delivered to non-target sites. To solve this problem, in this study, a drug-enclosed needle-type starch implant was developed that can overcome IFP and remain in the tumor.

Methods

Injectable needle-type starch implants (NS implants) were prepared by starch gelatinization and drying. The structure, cytotoxicity, and anticancer effects of the NS implants were evaluated. Biodistribution of NS implants was evaluated in pork (in vitro), dissected liver (ex vivo), and 4T1 tumors in mice (in vivo) using a fluorescence imaging device.

Results

The prepared NS implants exhibited a hydrogel structure after water absorption. NS implants showed effective cytotoxicity and anticancer effects by photothermal therapy (PTT). The NS implant itself has sufficient strength and can be easily injected into a desired area. In vivo, the NS implant continuously delivered drugs to the tumor more effectively and uniformly than conventional hydrogels and solutions.

Conclusion

This study demonstrated the advantages of needle-type implants. An injectable NS implant can be a new formulation that can effectively deliver drugs and exhibit anticancer effects.

Fluidic enabled bioelectronic implants: opportunities and challenges

Bioelectronic implants are increasingly facilitating novel strategies for clinical diagnosis and treatment. The integration of fluidic technologies into such implants enables new complementary routes for sensing and therapy alongside electrical interaction. Indeed, these two technologies, electrical and fluidic, can work synergistically in a bioelectronics implant towards the fabrication of a complete therapeutic platform. In this perspective article, the leading applications of fluidic enabled bioelectronic implants are highlighted and methods of operation and material choices are discussed. Furthermore, a forward-looking perspective is offered on emerging opportunities as well as critical materials and technological challenges.

3D and 4D Printing in the Fight against Breast Cancer

Breast cancer is the second most common cancer worldwide, characterized by a high incidence and mortality rate. Despite the advances achieved in cancer management, improvements in the quality of life of breast cancer survivors are urgent. Moreover, considering the heterogeneity that characterizes tumors and patients, focusing on individuality is fundamental. In this context, 3D printing (3DP) and 4D printing (4DP) techniques allow for a patient-centered approach. At present, 3DP applications against breast cancer are focused on three main aspects: treatment, tissue regeneration, and recovery of the physical appearance. Scaffolds, drug-loaded implants, and prosthetics have been successfully manufactured; however, some challenges must be overcome to shift to clinical practice. The introduction of the fourth dimension has led to an increase in the degree of complexity and customization possibilities. However, 4DP is still in the early stages; thus, research is needed to prove its feasibility in healthcare applications. This review article provides an overview of current approaches for breast cancer management, including standard treatments and breast reconstruction strategies. The benefits and limitations of 3DP and 4DP technologies are discussed, as well as their application in the fight against breast cancer. Future perspectives and challenges are outlined to encourage and promote AM technologies in real-world practice.

On-demand delivery of protein drug from 3D-printed implants

Here, we constructed 3D-printed multiunit implants to enable remote light-controlled protein drug delivery in a spatiotemporal manner. Multiunit implants were designed to be 3D printed using polycaprolactone, lauric acid, and melanin as a matrix, and a polycaprolactone scaffold as a multiunit divider. As a model drug, insulin was loaded to each unit of the implant. The 3D printing yielded a rectangular matrix with multiunit sectors segregated by polycaprolactone lanes. Irradiation with near infrared light (NIR) triggered controlled release of insulin from the irradiated locus: Upon NIR irradiation, heat generated from the melanin melted the polycaprolactone/lauric acid matrix to release insulin from the scaffold. In the absence of melanin in the matrix, the implant did not show NIR-responsive insulin release. When lauric acid was absent from the matrix, the NIR-irradiated unit did not undergo dismantling. When the insulin-loaded multiunit implant was applied to a mouse diabetic model and irradiated with NIR, repetitive insulin release resulted in an efficient decrease of the blood glucose level over multiple days. Together, these results suggest that 3D printing technology-based multi-dosing of insulin on demand can enable convenient treatment of diabetes through external NIR irradiation, potentially avoiding the pain and discomfort of repeated insulin injections.

Implantable Sandwich-like Scaffold/Fiber Composite Spatiotemporally Releasing Combretastatin A4 and Doxorubicin for Efficient Inhibition of Postoperative Tumor Recurrence

Tumor recurrence is a critical conundrum in the postoperative therapy, on account of severe bleeding with disseminated tumor cells, residual tumor cells, and the rich nutrient and oxygen supply transported to tumors by the abundant blood vessels. Biodegradable drug-loaded implants, inserted in the resection cavity right away upon the surgery, possess bleeding prevention and efficient chemotherapeutic capabilities, considered to be a promising strategy to efficiently inhibit the recurrence of the solid tumor. Here, we developed a sandwich-like composite consisting of the combretastatin A4 (CA4)-loaded 3D-printed scaffold and doxorubicin (DOX)-loaded electrospun fiber (Scaffold-CA4@Fiber-DOX), presenting hemostatic, chemotherapeutic, and antibacterial potencies. The lyophilized 3D-printed scaffold with a porous structure rapidly absorbed and clotted the blood cells and disseminated tumor cells to prevent bleeding and tumor metastasis. Subsequently, the preferentially released CA4 from the scaffold disrupted the microtubules of the vascular endothelial cell, resulting in vascular deformation and consequent insufficient nutrient supply to the solid tumor. The sustained release of DOX from the sandwiched electrospun fiber dramatically inhibited the peripheral tumor cell proliferation. This all-in-one multifunctional implant system, combining efficient vascular disruption and chemotherapy, provides a promising strategy for postoperative tumor therapy.

Application of additively manufactured 3D scaffolds for bone cancer treatment: a review

Bone cancer is a critical health problem on a global scale, and the associated huge clinical and economic burdens are still rising. Although many clinical approaches are currently used for bone cancer treatment, these methods usually affect the normal body functions and thus present significant limitations. Meanwhile, advanced materials and additive manufacturing have opened up promising avenues for the development of new strategies targeting both bone cancer treatment and post-treatment bone regeneration. This paper presents a comprehensive review of bone cancer and its current treatment methods, particularly focusing on a number of advanced strategies such as scaffolds based on advanced functional materials, drug-loaded scaffolds, and scaffolds for photothermal/magnetothermal therapy. Finally, the main research challenges and future perspectives are elaborated.

Implantable Devices for the Treatment of Breast Cancer

Breast cancer is one of the leading causes of death in the female population worldwide. Standard treatments such as chemotherapy show noticeable results. However, along with killing cancer cells, it causes systemic toxicity and apoptosis of the nearby healthy cells, therefore patients must endure side effects during the treatment process. Implantable drug delivery devices that enhance therapeutic efficacy by allowing localized therapy with programmed or controlled drug release can overcome the shortcomings of conventional treatments. An implantable device can be composed of biopolymer materials, nanocomposite materials, or a combination of both. This review summarizes the recent research and current state-of-the art in these types of implantable devices and gives perspective for future directions.

3D-Printed Coaxial Hydrogel Patches with Mussel-Inspired Elements for Prolonged Release of Gemcitabine

With the aim of fabricating drug-loaded implantable patches, a 3D printing technique was employed to produce novel coaxial hydrogel patches. The core-section of these patches contained a dopamine-modified methacrylated alginate hydrogel loaded with a chemotherapeutic drug (Gemcitabine), while their shell section was solely comprised of a methacrylated alginate hydrogel. Subsequently, these patches were further modified with CaCO3 cross linker and a polylactic acid (PLA) coating to facilitate prolonged release of the drug. Consequently, the results showed that addition of CaCO3 to the formula enhanced the mechanical properties of the patches and significantly reduced their swelling ratio as compared to that for patches without CaCO3. Furthermore, addition of PLA coating to CaCO3-containing patches has further reduced their swelling ratio, which then significantly slowed down the release of Gemcitabine, to a point where 4-layered patches could release the drug over a period of 7 days in vitro. Remarkably, it was shown that 3-layered and 4-layered Gemcitabine loaded patches were successful in inhibiting pancreatic cancer cell growth for a period of 14 days when tested in vitro. Lastly, in vivo experiments showed that gemcitabine-loaded 4-layered patches were capable of reducing the tumor growth rate and caused no severe toxicity when tested in mice. Altogether, 3D printed hydrogel patches might be used as biocompatible implants for local delivery of drugs to diseased site, to either shrink the tumor or to prevent the tumor recurrence after resection.

Synergistic Cascade Strategy Based on Modifying Tumor Microenvironment for Enhanced Breast Cancer Therapy

Background: Triple-negative breast cancer (TNBC) is the most aggressive subtype of breast cancer with very few treatment options. Although tumor-targeted nanomedicines hold great promise for the treatment of TNBC, the tumor microenvironment (TME) continues to be a major cause of failure in nanotherapy and immunotherapy. To overcome this barrier, we designed a new synergistic cascade strategy (SCS) that uses mild hyperthermia and smart drug delivery system (SDDS) to alter TME resistance in order to improve drug delivery and therapeutic efficacy of TNBC. Methods: Mild hyperthermia was produced by microwave (MW) irradiation. SDDS were formulated with thermosensitive polymer-lipid nanoparticles (HA-BNPs@Ptx), composed of polymer PLGA, phospholipid DPPC, hyaluronic acid (HA, a differentiation-44-targeted molecule, also known as CD44), 1-butyl-3-methylimidazolium-L-lactate (BML, a MW sensitizer), and paclitaxel (Ptx, chemotherapy drug). 4T1 breast tumor-bearing mice were treated with two-step MW combined with HA-BNPs@Ptx. Tumors in mice were pretreated with first MW irradiation prior to nanoparticle injection to modify and promote TME and promoting nanoparticle uptake and retention. The second MW irradiation was performed on the tumor 24 h after the injection of HA-BNPs@Ptx to produce a synergistic cascade effect through activating BML, thus, enhancing a hyperthermia effect, and instantly releasing Ptx at the tumor site. Results: Multifunctional CD44-targeted nanoparticles HA-BNPs@Ptx were successfully prepared and validated in vitro. After the first MW irradiation of tumors in mice, the intratumoral perfusion increased by two times, and the nanoparticle uptake was augmented by seven times. With the second MW irradiation, remarkable antitumor effects were obtained with the inhibition rate up to 88%. In addition, immunohistochemical analysis showed that SCS therapy could not only promote tumor cell apoptosis but also significantly reduce lung metastasis. Conclusion: The SCS using mild hyperthermia combined with SDDS can significantly improve the efficacy of TNBC treatment in mice by modifying TME and hyperthermia-mediated EPR effects.

3D Printed Personalized Medicine for Cancer: Applications for Betterment of Diagnosis, Prognosis and Treatment

Cancer treatment is challenging due to the tumour heterogeneity that makes personalized medicine a suitable technique for providing better cancer treatment. Personalized medicine analyses patient-related factors like genetic make-up and lifestyle and designs treatments that offer the benefits of reduced side effects and efficient drug delivery. Personalized medicine aims to provide a holistic way for prevention, diagnosis and treatment. The customization desired in personalized medicine is produced accurately by 3D printing which is an established technique known for its precision. Different 3D printing techniques exhibit their capability in producing cancer-specific medications for breast, liver, thyroid and kidney tumours. Three-dimensional printing displays major influence on cancer modelling and studies using cancer models in treatment and diagnosis. Three-dimensional printed personalized tumour models like physical 3D models, bioprinted models and tumour-on-chip models demonstrate better in vitro and in vivo correlation in drug screening, cancer metastasis and prognosis studies. Three-dimensional printing helps in cancer modelling; moreover, it has also changed the facet of cancer treatment. Improved treatment via custom-made 3D printed devices, implants and dosage forms ensures the delivery of anticancer agents efficiently. This review covers recent applications of 3D printed personalized medicine in various cancer types and comments on the possible future directions like application of 4D printing and regularization of 3D printed personalized medicine in healthcare.

Biopolymer Hydrogel Scaffolds Containing Doxorubicin as A Localized Drug Delivery System for Inhibiting Lung Cancer Cell Proliferation

A hydrogel scaffold is a localized drug delivery system that can maintain the therapeutic level of drug concentration at the tumor site. In this study, the biopolymer hydrogel scaffold encapsulating doxorubicin was fabricated from gelatin, sodium carboxymethyl cellulose, and gelatin/sodium carboxymethyl cellulose mixture using a lyophilization technique. The effects of a crosslinker on scaffold morphology and pore size were determined using scanning electron microscopy. The encapsulation efficiency and the release profile of doxorubicin from the hydrogel scaffolds were determined using UV-Vis spectrophotometry. The anti-proliferative effect of the scaffolds against the lung cancer cell line was investigated using an MTT assay. The results showed that scaffolds made from different types of natural polymer had different pore configurations and pore sizes. All scaffolds had high encapsulation efficiency and drug-controlled release profiles. The viability and proliferation of A549 cells, treated with gelatin, gelatin/SCMC, and SCMC scaffolds containing doxorubicin significantly decreased compared with control. These hydrogel scaffolds might provide a promising approach for developing a superior localized drug delivery system to kill lung cancer cells.

An updated review on application of 3D printing in fabricating pharmaceutical dosage forms

The concept of "one size fits all" followed by the conventional healthcare system has drawbacks in providing precise pharmacotherapy due to variation in the pharmacokinetics of different patients leading to serious consequences such as side effects. In this regard, digital-based three-dimensional printing (3DP), which refers to fabricating 3D printed pharmaceutical dosage forms with variable geometry in a layer-by-layer fashion, has become one of the most powerful and innovative tools in fabricating "personalized medicine" to cater to the need of therapeutic benefits for patients to the maximum extent. This is achieved due to the tremendous potential of 3DP in tailoring various drug delivery systems (DDS) in terms of size, shape, drug loading, and drug release. In addition, 3DP has a huge impact on special populations including pediatrics, geriatrics, and pregnant women with unique or frequently changing medical needs. The areas covered in the present article are as follows: (i) the difference between traditional and 3DP manufacturing tool, (ii) the basic processing steps involved in 3DP, (iii) common 3DP methods with their pros and cons, (iv) various DDS fabricated by 3DP till date with discussing few research studies in each class of DDS, (v) the drug loading principles into 3D printed dosage forms, and (vi) regulatory compliance.

Polymeric long-acting drug delivery systems (LADDS) for treatment of chronic diseases: Inserts, patches, wafers, and implants

Non-oral long-acting drug delivery systems (LADDS) encompass a range of technologies for precisely delivering drug molecules into target tissues either through the systemic circulation or via localized injections for treating chronic diseases like diabetes, cancer, and brain disorders as well as for age-related eye diseases. LADDS have been shown to prolong drug release from 24 h up to 3 years depending on characteristics of the drug and delivery system. LADDS can offer potentially safer, more effective, and patient friendly treatment options compared to more invasive modes of drug administration such as repeated injections or minor surgical intervention. Whilst there is no single technology or definition that can comprehensively embrace LADDS; for the purposes of this review, these systems include solid implants, inserts, transdermal patches, wafers and in situ forming delivery systems. This review covers common chronic illnesses, where candidate drugs have been incorporated into LADDS, examples of marketed long-acting pharmaceuticals, as well as newly emerging technologies, used in the fabrication of LADDS.

Polymeric implants with drug-releasing capabilities: a mapping review of laboratory research

PURPOSE

To provide a systematic map of the nature and extent of preclinical research concerning drug-releasing polymeric implants.

SIGNIFICANCE

By summarizing available data, this mapping review can guide the development of new drug-delivery devices.

METHODS

In-vitro studies assessing drug-delivery implants were reviewed. A study protocol was registered at Open Science Framework. The association of polymers with prominent drugs, manufacturing processes, geometries, treatments, and anatomical locations was assessed using the VOSviewer software. The release periods were also evaluated.

RESULTS

A total of 423 articles, published between 1975 and 2020, were included and grouped into a framework with nine main categories. More than half of studies were published between 2010 and 2020. Among 201 individual polymers or combinations, the most investigated were PLGA, PCL, PLA, Silicone (SIL), EVA, and PU. Similarly, from 232 individual drugs or combinations, the most prominent were dexamethasone (DEX; anti-inflammatory), paclitaxel (PTX; anticancer), fluoruracil (anticancer), ciprofloxacin (CFX) hydrochloride (antibiotic), and gentamicin (GS; antibiotic). A total of 51 manufacturing processes were encountered, of which the most reported were solvent evaporation, compression molding (CM), extrusion (EX), electrospinning (ELS), and melt molding (MM). Among 38 implant geometries, cylinder (CIL) was the most prominent, followed by disk, square film, circular film (FCIR), and undefined film. Release times varied greatly, although the majority of articles ranged between 5 and 300 d.

CONCLUSIONS

Drug-delivery implants were highly heterogeneous due to its applicability for multiple health conditions. Most implants were made of PLGA and most drugs assessed presented anti-inflammatory, antibiotic, or anticancer effects. Solvent evaporation and CIL were the most prominent manufacturing process and geometry, respectively.

Exploration and Preparation of Patient-specific Ciprofloxacin Implants Drug Delivery System Via 3D Printing Technologies

A suitable drug-loaded implant delivery system that can effectively release antibacterial drug in the postoperative lesion area and help repair bone infection is very significant in the clinical treatment of bone defect. The work was aimed to investigate the feasibility of applying three-dimensional (3D) printing technology to prepare drug-loaded implants for bone repair. Semi-solid extrusion (SSE) and Fuse deposition modeling® (FDM) technologies were implemented and ciprofloxacin (CIP) was chosen as the model drug. All of the implants exhibited a smooth surface, good mechanical properties and satisfactory structural integrity as well as accurate dimensional size. In vitro drug release showed that the implants made by 3D printing technologies slowed down the initial drug burst effect and expressed a long-term sustained release behavior, compared with the implants prepared with traditional method. In addition, the patient-specific macrostructure implants, consisting of interconnected and different shapes pores, were created using unique lay down patterns. As a result, the weakest burst release effect and the sustained drug release were achieved in the patient-specific implants with linear pattern. These results clearly stated that 3D printing technology offers a viable approach to prepare control-releasing implants with patient-specific macro-porosity and presents novel strategies for treating bone infections.

3D-Printing of Drug-Eluting Implants: An Overview of the Current Developments Described in the Literature

The usage of 3D-printing for drug-eluting implants combines the advantages of a targeted local drug therapy over longer periods of time at the precise location of the disease with a manufacturing technique that easily allows modifications of the implant shape to comply with the individual needs of each patient. Research until now has been focused on several aspects of this topic such as 3D-printing with different materials or printing techniques to achieve implants with different shapes, mechanical properties or release profiles. This review is intended to provide an overview of the developments currently described in the literature. The topic is very multifaceted and several of the investigated aspects are not related to just one type of application. Consequently, this overview deals with the topic of 3D-printed drug-eluting implants in the application fields of stents and catheters, gynecological devices, devices for bone treatment and surgical screws, antitumoral devices and surgical meshes, as well as other devices with either simple or complex geometry. Overall, the current findings highlight the great potential of the manufacturing of drug-eluting implants via 3D-printing technology for advanced individualized medicine despite remaining challenges such as the regulatory approval of individualized implants.

Review on Computer-Aided Design and Manufacturing of Drug Delivery Scaffolds for Cell Guidance and Tissue Regeneration

In the last decade, additive manufacturing (AM) processes have updated the fields of biomaterials science and drug delivery as they promise to realize bioengineered multifunctional devices and implantable tissue engineering (TE) scaffolds virtually designed by using computer-aided design (CAD) models. However, the current technological gap between virtual scaffold design and practical AM processes makes it still challenging to realize scaffolds capable of encoding all structural and cell regulatory functions of the native extracellular matrix (ECM) of health and diseased tissues. Indeed, engineering porous scaffolds capable of sequestering and presenting even a complex array of biochemical and biophysical signals in a time- and space-regulated manner, require advanced automated platforms suitable of processing simultaneously biomaterials, cells, and biomolecules at nanometric-size scale. The aim of this work was to review the recent scientific literature about AM fabrication of drug delivery scaffolds for TE. This review focused on bioactive molecule loading into three-dimensional (3D) porous scaffolds, and their release effects on cell fate and tissue growth. We reviewed CAD-based strategies, such as bioprinting, to achieve passive and stimuli-responsive drug delivery scaffolds for TE and cancer precision medicine. Finally, we describe the authors' perspective regarding the next generation of CAD techniques and the advantages of AM, microfluidic, and soft lithography integration for enhancing 3D porous scaffold bioactivation toward functional bioengineered tissues and organs.

Facile and scalable fabrication of Ni cantilever nanoprobes using silicon template and micro-electroforming techniques for nano-tip focused electrohydrodynamic jet printing

Electrohydrodynamic jet (E-Jet) printing is a powerful technique for micro/nanostructure fabrication with high resolution and efficiency. However, conventional E-Jet printing are still limited in printing accuracy and ink adaptability due to the nozzle clogging effect. In this paper, we develop a nano-tip focused electrohydrodynamic jet (NFEJ) method to print high-resolution structures. The Ni cantilever nanoprobes with nanoscale radius of curvature (ROC) on their tips were manufactured by a facile and scalable method using silicon template and micro-electroforming technique. Scanning electron microscope was used to analyse the micromorphology of the silicon template with inverted pyramid pits, which was obtained from anisotropic wet etching of silicon. Electroforming mold was obtained by photolithography and plasma etching which divide the top side of Ni film into isolated cantilever pits. Ni cantilever nanoprobes with an average tip ROC of about 48 nm were achieved by the subsequent micro electroforming process. High-resolution droplets array with an average diameter of about 890 ± 93 nm were printed by the NFEJ printing head equipped with these Ni nanoprobes, which verified the practicality of the developed Ni nanoprobes for NFEJ printing.

Microtip focused electrohydrodynamic jet printing with nanoscale resolution

Electrohydrodynamic jet (E-Jet) printing is a promising manufacturing technique for micro-/nano-patterned structures with high resolution, high efficiency and high material compatibility. However, further improvement of the necking ratio of the E-Jet is still limited by the focusing principle. Moreover, ink viscosity is limited to values well below 90 mPa s owing to the high probability of nozzle blockage. Here, we propose a microtip focused electrohydrodynamic jet (MFEJ) printing to overcome these limitations. This technique uses a solid microtip with a radius of curvature (ROC) of several micrometers rather than a hollow nozzle, which is very simple and highly efficient to prepare and can effectively avoid nozzle clogging problems even with high-viscosity printing ink. High-resolution patterns in diverse geometries were printed using different inks with a wide range of viscosities (8.4-3500 mPa s). Nanodroplets with an average diameter of 73 nm were achieved. Moreover, nanofibers with a diameter of 30 nm were obtained using a 4 μm ROC microtip and the necking ratio was as high as 266 : 1. To the best of our knowledge, this is the smallest droplet or fiber diameter directly obtained via E-Jet printing to date without further physical or chemical processing. This MFEJ printing technique can improve printing resolution at the nanoscale, significantly enlarge the material applicability and effectively avoid nozzle clogging for the fabrication of nanodevices.

Functional 3D printing: Approaches and bioapplications

3D printing technology has become a mature manufacturing technique, widely used for its advantages over the traditional methods, such as the end-user customization and rapid prototyping, useful in different application fields, including the biomedical one. Indeed, it represents a helpful tool for the realization of biodevices (i.e. biosensors, microfluidic bioreactors, drug delivery systems and Lab-On-Chip). In this perspective, the development of 3D printable materials with intrinsic functionalities, through the so-called 4D printing, introduces novel opportunities for the fabrication of "smart" or stimuli-responsive devices. Indeed, functional 3D printable materials can modify their surfaces, structures, properties or even shape in response to specific stimuli (such as pressure, temperature or light radiation), adding to the printed object new interesting properties exploited after the fabrication process. In this context, by combining 3D printing technology with an accurate materials' design, functional 3D objects with built-in (bio)chemical functionalities, having biorecognition, biocatalytic and drug delivery capabilities are here reported.

Immunostimulatory biomaterials to boost tumor immunogenicity

Cancer immunotherapy is exhibiting great promise as a new therapeutic modality for cancer treatment. However, immunotherapies are limited by the inability of some tumors to provoke an immune response. These tumors with a 'cold' immunological phenotype are characterized by low numbers of tumor-infiltrating lymphocytes, high numbers of immunosuppressive leukocytes (e.g. regulatory T cells, tumor-associated macrophages), and high production of immune-dampening signals (e.g. IL-10, TGF-β, IDO-1). Strategies to boost the aptitude of tumors to initiate an immune response (i.e. boost tumor immunogenicity) will turn 'cold' tumors 'hot' and augment the anti-tumor efficacy of current immunotherapies. Approaches to boost tumor immunogenicity already show promise; however, multifaceted delivery and immunobiology challenges exist. For instance, systemic delivery of many immune-stimulating agents causes off-target toxicity and/or the development of autoimmunity, limiting the administrable dose below the threshold needed to achieve efficacy. Moreover, once administered in vivo, molecules such as the nucleic acid-based agonists for many pattern recognition receptors are either rapidly cleared or degraded, and don't efficiently traffic to the intracellular compartments where the receptors are located. Thus, these nucleic acid-based drugs are ineffective without a delivery system. Biomaterials-based approaches aim to enhance current strategies to boost tumor immunogenicity, enable novel strategies, and spare dose-limiting toxicities. Here, we review recent progress to improve cancer immunotherapies by boosting immunogenicity within tumors using immunostimulatory biomaterials.

3D printed intelligent scaffold prevents recurrence and distal metastasis of breast cancer

Rationale: Tumors are commonly treated by resection, which usually leads to massive hemorrhage and tumor cell residues, thereby increasing the risk of local recurrence and distant metastasis.

Methods: Herein, an intelligent 3D-printed poly(lactic-co-glycolic acid), gelatin, and chitosan scaffold loaded with anti-cancer drugs was prepared that showed hemostatic function and good pH sensitivity.

Results: Following in situ implantation in wounds, the scaffolds absorbed hemorrhage and cell residues after surgery, and promoted wound healing. In an in vivo environment, the scaffold responded to the slightly acidic environment of the tumor to undergo sustained drug release to significantly inhibit the recurrence and growth of the tumor, and reduced drug toxicity, all without causing damage to healthy tissues and with good biocompatibility.

Conclusions: The multifunctional intelligent scaffold represents an excellent treatment modality for breast cancer following resection, and provides great potential for efficient cancer therapy.

Preparation and characterization of abalone shells derived biological mesoporous hydroxyapatite microspheres for drug delivery

The rapid growth of the abalone industry has brought a great burden to the environment because of their inedible shells. Aiming at environmental and resource sustainability, porous microspheres of carbonate-substituted hydroxyapatite (HAP) were prepared by a hydrothermal method using abalone shells; then, they were further used as a carrier for doxorubicin (DOX) in a drug delivery system. The porous HAP microspheres were approximately 6 μm in size with a considerable specific surface area and average pore size (128.6659 cm²/g and 9.064 nm, respectively), which ensured excellent drug-handling capacity (95.542%). In addition, the pH responsiveness of the drug release system was favorable for effective in vivo drug release in an acidic tumor microenvironment. Moreover, the drug-loaded microspheres could effectively induce apoptosis of MCF-7 cells but were less cytotoxic to MC3T3-E1 cells. Because of its good biocompatibility, high drug loading capacity and controlled drug release property, the porous microspheres prepared in this experiment have potential application value in drug delivery and tumor therapy; furthermore, they make full use of abalone shells, providing environmental sustainability.

Synthesis and Characterization of Inulin-Based Responsive Polyurethanes for Breast Cancer Applications

In this study, new polyurethanes (PUs) were prepared by using inulin and polycaprolactone as polyols. Their structure and morphology were determined by Fourier transform infrared spectroscopy (FTIR), Raman dispersive spectroscopy, Nuclear magnetic resonance spectroscopy (¹H NMR and ¹³C NMR), and scanning electron microscopy (SEM), whereas their mechanical properties were evaluated by a universal testing machine. Additionally, their water uptake, swelling behavior, and degradation were evaluated to be used as drug delivery carriers. Therefore, an anti-cancer drug was loaded to these PUs with 25% of loading efficiency and its release behavior was studied using different theoretical models to unveil its mechanism. Finally, the ability of the new PUs to be used as a clip marker in breast biopsy was evaluated. The results clearly demonstrate that these PUs are safe and can be used as intelligent drug release matrices for targeted drug delivery and exhibits positive results to be used for clip marker and in general for breast cancer applications.

Novel Honokiol-eluting PLGA-based scaffold effectively restricts the growth of renal cancer cells

Renal Cell Carcinoma (RCC) often becomes resistant to targeted therapies, and in addition, dose-dependent toxicities limit the effectiveness of therapeutic agents. Therefore, identifying novel drug delivery approaches to achieve optimal dosing of therapeutic agents can be beneficial in managing toxicities and to attain optimal therapeutic effects. Previously, we have demonstrated that Honokiol, a natural compound with potent anti-tumorigenic and anti-inflammatory effects, can induce cancer cell apoptosis and inhibit the growth of renal tumors in vivo. In cancer treatment, implant-based drug delivery systems can be used for gradual and sustained delivery of therapeutic agents like Honokiol to minimize systemic toxicity. Electrospun polymeric fibrous scaffolds are ideal candidates to be used as drug implants due to their favorable morphological properties such as high surface to volume ratio, flexibility and ease of fabrication. In this study, we fabricated Honokiol-loaded Poly(lactide-co-glycolide) (PLGA) electrospun scaffolds; and evaluated their structural characterization and biological activity. Proton nuclear magnetic resonance data proved the existence of Honokiol in the drug loaded polymeric scaffolds. The release kinetics showed that only 24% of the loaded Honokiol were released in 24hr, suggesting that sustained delivery of Honokiol is feasible. We calculated the cumulative concentration of the Honokiol released from the scaffold in 24hr; and the extent of renal cancer cell apoptosis induced with the released Honokiol is similar to an equivalent concentration of direct application of Honokiol. Also, Honokiol-loaded scaffolds placed directly in renal cell culture inhibited renal cancer cell proliferation and migration. Together, we demonstrate that Honokiol delivered through electrospun PLGA-based scaffolds is effective in inhibiting the growth of renal cancer cells; and our data necessitates further in vivo studies to explore the potential of sustained release of therapeutic agents-loaded electrospun scaffolds in the treatment of RCC and other cancer types.