Gene Therapy for Regenerative Medicine

Advancement of Nanomaterials- and Biomaterials-Based Technologies for Wound Healing and Tissue Regenerative Applications

Patients and healthcare systems face significant social and financial challenges due to the increasing number of individuals with chronic external and internal wounds that fail to heal. The complexity of the healing process remains a serious health concern, despite the effectiveness of conventional wound dressings in promoting healing. Recent advancements in materials science and fabrication techniques have led to the development of innovative dressings that enhance wound healing. To further expedite the healing process, novel approaches such as nanoparticles, 3D-printed wound dressings, and biomolecule-infused dressings have emerged, along with cell-based methods. Additionally, gene therapy technologies are being harnessed to generate stem cell derivatives that are more functional, selective, and responsive than their natural counterparts. This review highlights the significant potential of biomaterials, nanoparticles, 3D bioprinting, and gene- and cell-based therapies in wound healing. However, it also underscores the necessity for further research to address the existing challenges and integrate these strategies into standard clinical practice.

Conventional and microfluidic methods: Design and optimization of lipid-polymeric hybrid nanoparticles for gene therapy

Gene therapy holds significant promise as a therapeutic approach for addressing a diverse range of diseases through the suppression of overexpressed proteins and the restoration of impaired cell functions. Developing a nanocarrier that can efficiently load and release genetic material into cells remains a challenge. The primary goal of this study is to develop formulations aimed to enhance the therapeutic potential of GapmeRs through technological approaches. To this end, lipid-polymeric hybrid nanoparticles (LPHNPs) with PLGA, DC-cholesterol, and DOPE-mPEG2000 were produced by conventional single-step nanoprecipitation (SSN) and microfluidic (MF) methods. The optimized nanoparticles by SSN have a size of 149.9 ± 18.07 nm, a polydispersity index (PdI) of 0.23 ± 0.02, and a zeta potential of (ZP) of 29.34 ± 2.44 mV, while by MF the size was 179.8 ± 6.3, a PdI of 0.24 ± 0.01, and a ZP of 32.25 ± 1.36 mV. Furthermore, LPHNPs prepared with GapmeR-protamine by both methods exhibit a high encapsulation efficiency of approximately 90%. The encapsulated GapmeR is completely released in 24 h. The LPHNP suspensions are stable for up to 6 h in 10% FBS at pH 5.4 and 7.4. By contrast, LPHNPs remain stable in suspension in 4.5% albumin at pH 7.4 for 24 h. Additionally, LPHNPs were successfully freeze-dried using trehalose in the range of 2.5-5% as cryoprotectant The LPHNPs produced by MF and SSN increase, 6 and 12 fold respectively, GapmeR cell uptake, and both of them reduce by 60-70% expression of Tob1 in 48 h.Our study demonstrates the efficacy of the developed LPHNPs as carriers for oligonucleotide delivery, offering valuable insights for their scale up production from a conventional bulk methodology to a high-throughput microfluidic technology.

Gene doping in horse racing and equine sports: Current landscape and future perspectives

Gene doping, the use of gene therapy or genetic manipulation to enhance athletic performance, has emerged as a potential threat to the integrity and welfare of equine sports, such as horse racing and equestrian sports. This review aims to provide an overview of gene doping in horses, including the underlying technologies, potential applications, detection methods, ethical concerns and future perspectives. By understanding the current landscape of gene doping in horses, stakeholders can work together to develop strategies to safeguard the integrity of equine sports.

Advances in regenerative medicine-based approaches for skin regeneration and rejuvenation

Significant progress has been made in regenerative medicine for skin repair and rejuvenation. This review examines core technologies including stem cell therapy, bioengineered skin substitutes, platelet-rich plasma (PRP), exosome-based therapies, and gene editing techniques like CRISPR. These methods hold promise for treating a range of conditions, from chronic wounds and burns to age-related skin changes and genetic disorders. Challenges remain in optimizing these therapies for broader accessibility and ensuring long-term safety and efficacy.

Phytonanoparticles as novel drug carriers for enhanced osteogenesis and osseointegration

Phytonanoparticles have emerged as a promising class of biomaterials for enhancing bone regeneration and osseointegration, offering unique advantages in biocompatibility, multifunctionality, and sustainability. This comprehensive review explores the synthesis, characterization, and applications of phytonanoparticles in bone tissue engineering. The green synthesis approach, utilizing plant extracts as reducing and stabilizing agents, yields nanoparticles with intrinsic bioactive properties that can synergistically promote osteogenesis. We examine the mechanisms by which phytonanoparticles, particularly those derived from gold, silver, and zinc oxide, influence key molecular pathways in osteogenesis, including RUNX2 and Osterix signaling. The review discusses advanced strategies in phyto-nanoparticle design, such as surface functionalization and stimuli-responsive release mechanisms, which enhance their efficacy in bone regeneration applications. Preclinical studies demonstrating improved osteoblast proliferation, differentiation, and mineralization are critically analyzed, along with emerging clinical data. Despite promising results, scalability, standardization, and regulatory approval challenges persist. The review also addresses the economic and environmental implications of phyto-nanoparticle production. Looking ahead, we identify key research directions, including developing personalized therapies, combination approaches with stem cells or gene delivery, and long-term safety assessments. By harnessing the power of plant-derived nanomaterials, phytonanoparticles represent an innovative approach to addressing the complex challenges of bone regeneration, with potential applications spanning dental, orthopedic, and maxillofacial surgery.

Regeneration, Regengrow and Tissue Repair in Animals: Evolution Indicates That No Regeneration Occurs in Terrestrial Environments but Only Recovery Healing

The present, brief review paper summarizes previous studies on a new interpretation of the presence and absence of regeneration in invertebrates and vertebrates. Broad regeneration is considered exclusive of aquatic or amphibious animals with larval stages and metamorphosis, where also a patterning process is activated for whole-body regeneration or for epimorphosis. In contrast, terrestrial invertebrates and vertebrates can only repair injury or the loss of body parts through a variable "recovery healing" of tissues, regengrow or scarring. This loss of regeneration likely derives from the change in genomes during land adaptation, which included the elimination of larval stages and intense metamorphosis. The terrestrial conditions are incompatible with the formation of embryonic organs that are necessary for broad regeneration. In fact, no embryonic organ can survive desiccation, intense UV or ROS exposition on land, and rapid reparative processes without embryonic patterning, such as recovery healing and scarring, have replaced broad regeneration in terrestrial species. The loss of regeneration in land animals likely depends on the alteration of developmental gene pathways sustaining regeneration that occurred in progenitor marine animals. Terrestrial larval stages, like those present in insects among arthropods, only metamorphose using small body regions indicated as imaginal disks, a terrestrial adaptation, not from a large restructuring process like in aquatic-related animals. These invertebrates can reform body appendages only during molting, a process indicated as regengrow, not regeneration. Most amniotes only repair injuries through scarring or a variable recovery healing, occasionally through regengrow, the contemporaneous healing in conjunction with somatic growth, forming sometimes new heteromorphic organs.

Boosting Lipofection Efficiency Through Enhanced Membrane Fusion Mechanisms

Gene transfection is a fundamental technique in the fields of biological research and therapeutic innovation. Due to their biocompatibility and membrane-mimetic properties, lipid vectors serve as essential tools in transfection. The successful delivery of genetic material into the cytoplasm is contingent upon the fusion of the vector and cellular membranes, which enables hydrophilic polynucleic acids to traverse the hydrophobic barriers of two intervening membranes. This review examines the critical role of membrane fusion in lipofection efficiency, with a particular focus on the molecular mechanisms that govern lipoplex-membrane interactions. This analysis will examine the key challenges inherent to the fusion process, from achieving initial membrane proximity to facilitating final content release through membrane remodeling. In contrast to viral vectors, which utilize specialized fusion proteins, lipid vectors necessitate a strategic formulation and environmental optimization to enhance their fusogenicity. This review discusses recent advances in vector design and fusion-promoting strategies, emphasizing their potential to improve gene delivery yield. It highlights the importance of understanding lipoplex-membrane fusion mechanisms for developing next-generation delivery systems and emphasizes the need for continued fundamental research to advance lipid-mediated transfection technology.

From Bench to Bedside: Translating Cellular Rejuvenation Therapies into Clinical Applications

Cellular rejuvenation therapies represent a transformative frontier in addressing age-related decline and extending human health span. By targeting fundamental hallmarks of aging-such as genomic instability, epigenetic alterations, mitochondrial dysfunction, and cellular senescence-these therapies aim to restore youthful functionality to cells and tissues, offering new hope for treating degenerative diseases. Recent advancements have showcased a range of strategies, including epigenetic reprogramming, senolytic interventions, mitochondrial restoration, stem cell-based approaches, and gene-editing technologies like CRISPR. Each modality has demonstrated substantial potential in preclinical models and is now being cautiously explored in early-stage clinical trials. However, translating these therapies from the laboratory to clinical practice presents unique challenges: safety concerns, delivery precision, complex regulatory requirements, ethical considerations, and high costs impede widespread adoption. This review examines the current landscape of cellular rejuvenation, highlighting key advancements, potential risks, and the strategies needed to overcome these hurdles.

Progressive modifications during evolution involving epigenetic changes have determined loss of regeneration mainly in terrestrial animals: A hypothesis

In order to address a biological explanation for the different regenerative abilities present among animals, a new evolutionary speculation is presented. It is hypothesized that epigenetic mechanisms have lowered or erased regeneration during the evolution of terrestrial invertebrates and vertebrates. The hypothesis indicates that a broad regeneration can only occur in marine or freshwater conditions, and that life on land does not allow for high regeneration. This is due to the physical, chemical and microbial conditions present in the terrestrial environment with respect to those of the aquatic environment. The present speculation provides examples of hypothetic evolutionary animal lineages that colonized the land, such as parasitic annelids, terrestrial mollusks, arthropods and amniotes. These are the animals where regeneration is limited or absent and their injuries are only repaired through limited healing or scarring. It is submitted that this loss derived from changes in the developmental gene pathways sustaining regeneration in the aquatic environment but that cannot be expressed on land. Once regeneration was erased in terrestrial species, re-adaptation to freshwater niches could not reactivate the previously altered gene pathways that determined regeneration. Therefore a broad regeneration was no longer possible or became limited and heteromorphic in the derived, extant animals. Only in few cases extensive healing abilities or regengrow, a healing process where regeneration overlaps with somatic growth, have evolved among arthropods and amniotes. The present paper is an extension of previous speculations trying to explain in biological terms the different regenerative abilities present among metazoans.

Graphene-Oxide Peptide-Containing Materials for Biomedical Applications

This review explores the application of graphene-based materials (GBMs) in biomedicine, focusing on graphene oxide (GO) and its interactions with peptides and proteins. GO, a versatile nanomaterial with oxygen-containing functional groups, holds significant potential for biomedical applications but faces challenges related to toxicity and environmental impact. Peptides and proteins can be functionalized on GO surfaces through various methods, including non-covalent interactions such as π-π stacking, electrostatic forces, hydrophobic interactions, hydrogen bonding, and van der Waals forces, as well as covalent bonding through reactions involving amide bond formation, esterification, thiol chemistry, and click chemistry. These approaches enhance GO's functionality in several key areas: biosensing for sensitive biomarker detection, theranostic imaging that integrates diagnostics and therapy for real-time treatment monitoring, and targeted cancer therapy where GO can deliver drugs directly to tumor sites while being tracked by imaging techniques like MRI and photoacoustic imaging. Additionally, GO-based scaffolds are advancing tissue engineering and aiding tissues' bone, muscle, and nerve tissue regeneration, while their antimicrobial properties are improving infection-resistant medical devices. Despite its potential, addressing challenges related to stability and scalability is essential to fully harness the benefits of GBMs in healthcare.

Advances and Challenges in Gene Therapy for Inherited Retinal Dystrophies: A Comprehensive Review

Inherited retinal dystrophies (IRDs) are a diverse group of genetic disorders leading to progressive vision loss due to the degeneration of retinal photoreceptors. Gene therapy has emerged as a promising approach to address the underlying genetic causes of IRDs, offering the potential for restoring vision and halting disease progression. This review provides a comprehensive overview of gene therapy innovations for IRDs, focusing on the mechanisms, recent advancements, and ongoing challenges. We discuss the fundamental principles of gene therapy, including the use of viral and non-viral vectors, and highlight key developments such as the approval of Luxturna for RPE65-mediated retinal dystrophy and the application of gene editing technologies like CRISPR/Cas9. Despite these advancements, significant challenges remain, including vector delivery, long-term safety, and variable patient responses. This review also explores the future directions of gene therapy, emphasizing the need for further research to address these challenges and enhance therapeutic efficacy. By examining the current state of gene therapy for IRDs, this review aims to provide valuable insights into the potential for these treatments to transform the management of retinal diseases and improve the quality of life for affected individuals.

Photoreceptor-targeted extracellular vesicles-mediated delivery of Cul7 siRNA for retinal degeneration therapy

Rationale: Photoreceptor loss is a primary pathological feature of retinal degeneration (RD) with limited treatment strategies. RNA interference (RNAi) has emerged as a promising method of gene therapy in regenerative medicine. However, the transfer of RNAi therapeutics to photoreceptors and the deficiency of effective therapeutic targets are still major challenges in the treatment of RD. Methods: In this study, photoreceptor-derived extracellular vesicles (PEVs) conjugated with photoreceptor-binding peptide MH42 (PEVsMH42) were prepared using the anchoring peptide CP05. Transcriptome sequencing was applied to investigate the potential therapeutic target of RD. We then engineered PEVsMH42 with specific small-interfering RNAs (siRNAs) through electroporation and evaluated their therapeutic efficacy in N-methyl-N-nitrosourea (MNU)-induced RD mice and Pde6βrd1/rd1 mutant mice. Results: PEVsMH42 were selectively accumulated in photoreceptors after intravitreal injection. Cullin-7 (Cul7) was identified as a novel therapeutic target of RD. Taking advantage of the established PEVsMH42, siRNAs targeting Cul7 (siCul7) were efficiently delivered to photoreceptors and consequently blocked the expression of Cul7. Moreover, suppression of Cul7 effectively protected photoreceptors to alleviate RD both in MNU-induced mouse model and Pde6βrd1/rd1 mutant mouse model. Mechanistically, PEVsMH42 loaded with siCul7 (PEVsMH42-siCul7)-induced Cul7 downregulation was responsible for preventing Cul7-mediated glutathione peroxidase 4 (Gpx4) ubiquitination and degradation, resulting in the inhibition of photoreceptor ferroptosis. Conclusions: In summary, PEVsMH42-siCul7 attenuate photoreceptor ferroptosis to treat RD by inhibiting Cul7-induced ubiquitination of Gpx4. Our study develops a PEVs-based platform for photoreceptor-targeted delivery and highlights the potential of PEVsMH42-siCul7 as effective therapeutics for RD.

Enhancing hair regeneration: Recent progress in tailoring nanostructured lipid carriers through surface modification strategies

BACKGROUND AND PURPOSE

Hair loss is a prevalent problem affecting millions of people worldwide, necessitating innovative and efficient regrowth approaches. Nanostructured lipid carriers (NLCs) have become a hopeful option for transporting bioactive substances to hair follicles because of their compatibility with the body and capability to improve drug absorption.

REVIEW APPROACH

Recently, surface modification techniques have been used to enhance hair regeneration by improving the customization of NLCs. These techniques involve applying polymers, incorporating targeting molecules, and modifying the surface charge.

KEY RESULTS

The conversation focuses on how these techniques enhance stability, compatibility with the body, and precise delivery to hair follicles within NLCs. Moreover, it explains how surface-modified NLCs can improve the bioavailability of hair growth-promoting agents like minoxidil and finasteride. Furthermore, information on how surface-modified NLCs interact with hair follicles is given, uncovering their possible uses in treating hair loss conditions.

CONCLUSION

This review discusses the potential of altering the surface of NLCs to customize them for enhanced hair growth. It offers important information for upcoming studies on hair growth.

Advances in biomaterials for oral-maxillofacial bone regeneration: spotlight on periodontal and alveolar bone strategies

The intricate nature of oral-maxillofacial structure and function, coupled with the dynamic oral bacterial environment, presents formidable obstacles in addressing the repair and regeneration of oral-maxillofacial bone defects. Numerous characteristics should be noticed in oral-maxillofacial bone repair, such as irregular morphology of bone defects, homeostasis between hosts and microorganisms in the oral cavity and complex periodontal structures that facilitate epithelial ingrowth. Therefore, oral-maxillofacial bone repair necessitates restoration materials that adhere to stringent and specific demands. This review starts with exploring these particular requirements by introducing the particular characteristics of oral-maxillofacial bones and then summarizes the classifications of current bone repair materials in respect of composition and structure. Additionally, we discuss the modifications in current bone repair materials including improving mechanical properties, optimizing surface topography and pore structure and adding bioactive components such as elements, compounds, cells and their derivatives. Ultimately, we organize a range of potential optimization strategies and future perspectives for enhancing oral-maxillofacial bone repair materials, including physical environment manipulation, oral microbial homeostasis modulation, osteo-immune regulation, smart stimuli-responsive strategies and multifaceted approach for poly-pathic treatment, in the hope of providing some insights for researchers in this field. In summary, this review analyzes the complex demands of oral-maxillofacial bone repair, especially for periodontal and alveolar bone, concludes multifaceted strategies for corresponding biomaterials and aims to inspire future research in the pursuit of more effective treatment outcomes.

Tissue engineering and future directions in regenerative medicine for knee cartilage repair: a comprehensive review

This review evaluates the current landscape and future directions of regenerative medicine for knee cartilage repair, with a particular focus on tissue engineering strategies. In this context, scaffold-based approaches have emerged as promising solutions for cartilage regeneration. Synthetic scaffolds, while offering superior mechanical properties, often lack the biological cues necessary for effective tissue integration. Natural scaffolds, though biocompatible and biodegradable, frequently suffer from inadequate mechanical strength. Hybrid scaffolds, combining elements of both synthetic and natural materials, present a balanced approach, enhancing both mechanical support and biological functionality. Advances in decellularized extracellular matrix scaffolds have shown potential in promoting cell infiltration and integration with native tissues. Additionally, bioprinting technologies have enabled the creation of complex, bioactive scaffolds that closely mimic the zonal organization of native cartilage, providing an optimal environment for cell growth and differentiation. The review also explores the potential of gene therapy and gene editing techniques, including CRISPR-Cas9, to enhance cartilage repair by targeting specific genetic pathways involved in tissue regeneration. The integration of these advanced therapies with tissue engineering approaches holds promise for developing personalized and durable treatments for knee cartilage injuries and osteoarthritis. In conclusion, this review underscores the importance of continued multidisciplinary collaboration to advance these innovative therapies from bench to bedside and improve outcomes for patients with knee cartilage damage.

Advances of Recombinant Adenoviral Vectors in Preclinical and Clinical Applications

Adenoviruses (Ad) have the potential to induce severe infections in vulnerable patient groups. Therefore, understanding Ad biology and antiviral processes is important to comprehend the signaling cascades during an infection and to initiate appropriate diagnostic and therapeutic interventions. In addition, Ad vector-based vaccines have revealed significant potential in generating robust immune protection and recombinant Ad vectors facilitate efficient gene transfer to treat genetic diseases and are used as oncolytic viruses to treat cancer. Continuous improvements in gene delivery capacity, coupled with advancements in production methods, have enabled widespread application in cancer therapy, vaccine development, and gene therapy on a large scale. This review provides a comprehensive overview of the virus biology, and several aspects of recombinant Ad vectors, as well as the development of Ad vector, are discussed. Moreover, we focus on those Ads that were used in preclinical and clinical applications including regenerative medicine, vaccine development, genome engineering, treatment of genetic diseases, and virotherapy in tumor treatment.

A comprehensive review on structural and therapeutical insight of Cerebroside sulfotransferase (CST) - An important target for development of substrate reduction therapy against metachromatic leukodystrophy

This review is an effort towards the development of substrate reduction therapy using cerebroside sulfotransferase (CST) as a target protein for the development of inhibitors intended to treat pathophysiological condition resulting from the accumulation of sulfatide, a product from the catalytic action of CST. Accumulation of sulfatides leads to progressive impairment and destruction of the myelin structure, disruption of normal physiological transmission of electrical impulse between nerve cells, axonal loss in the central and peripheral nervous system and cumulatively gives a clinical manifestation of metachromatic leukodystrophy. Thus, there is a need to develop specific and potent CST inhibitors to positively control sulfatide accumulation. Structural similarity and computational studies revealed that LYS85, SER172 and HIS141 are key catalytic residues that determine the catalytic action of CST through the transfer of sulfuryl group from the donor PAPS to the acceptor galactosylceramide. Computational studies revealed catalytic site of CST consists two binding site pocket including PAPS binding pocket and substrate binding pocket. Specific substrate site residues in CST can be targeted to develop specific CST inhibitors. This review also explores the challenges of CST-directed substrate reduction therapy as well as the opportunities available in natural products for inhibitor development.

Exogenous alpha-linolenic acid and Vibrio parahaemolyticus induce EPA and DHA levels mediated by delta-6 desaturase to enhance shrimp immunity

Globally, penaeid shrimp are the most farmed and traded aquatic organisms, although they are easily susceptible to microbial pathogens. Moreover, there is a desire to increase the nutritional value of shrimp, especially the levels of n-3 polyunsaturated fatty acids (PUFAs), such as eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA), which also possess immunomodulatory and anti-inflammatory properties. Some aquatic animals can synthesize EPA and DHA from dietary plant-sourced alpha-linolenic acid (ALA), but penaeid shrimps' ability to synthesize these n-3 PUFAs is unknown. Here, molecular biology techniques, including gas chromatography-mass spectrometry, qPCR, ELISA, etc., were used to demonstrate that exogenous ALA or Vibrio parahaemolyticus could modulate EPA and DHA levels and immune genes in Penaeus vannamei by inducing key enzymes involved in n-3 PUFAs biosynthesis, such as delta desaturases and elongation of very long-chain fatty acid (ELOVLs). Most importantly, knockdown or inhibition of ∆6 desaturase significantly decreased EPA and DHA levels and immune gene expression even with exogenous ALA treatment, consequently affecting shrimp antibacterial immunity and survival. This study provides new insight into the potential of P. vannamei to synthesize n-3 PUFAs from exogenous ALA or upon bacteria challenge, which could be leveraged to increase their nutritional content and antimicrobial immunity.

Current Landscape of Gene Therapy for the Treatment of Cardiovascular Disorders

Cardiovascular disorders (CVD) are the primary cause of death worldwide. Multiple factors have been accepted to cause cardiovascular diseases; among them, smoking, physical inactivity, unhealthy eating habits, age, and family history are flag-bearers. Individuals at risk of developing CVD are suggested to make drastic habitual changes as the primary intervention to prevent CVD; however, over time, the disease is bound to worsen. This is when secondary interventions come into play, including antihypertensive, anti-lipidemic, anti-anginal, and inotropic drugs. These drugs usually undergo surgical intervention in patients with a much higher risk of heart failure. These therapeutic agents increase the survival rate, decrease the severity of symptoms and the discomfort that comes with them, and increase the overall quality of life. However, most individuals succumb to this disease. None of these treatments address the molecular mechanism of the disease and hence are unable to halt the pathological worsening of the disease. Gene therapy offers a more efficient, potent, and important novel approach to counter the disease, as it has the potential to permanently eradicate the disease from the patients and even in the upcoming generations. However, this therapy is associated with significant risks and ethical considerations that pose noteworthy resistance. In this review, we discuss various methods of gene therapy for cardiovascular disorders and address the ethical conundrum surrounding it.

The improving strategies and applications of nanotechnology-based drugs in hepatocellular carcinoma treatment

Hepatocellular carcinoma (HCC) is one of the leading causes of tumor-related death worldwide. Conventional treatments for HCC include drugs, radiation, and surgery. Despite the unremitting efforts of researchers, the curative effect of HCC has been greatly improved, but because HCC is often found in the middle and late stages, the curative effect is still not satisfactory, and the 5-year survival rate is still low. Nanomedicine is a potential subject, which has been applied to the treatment of HCC and has achieved promising results. Here, we summarized the factors affecting the efficacy of drugs in HCC treatment and the strategies for improving the efficacy of nanotechnology-based drugs in HCC, reviewed the recent applications' progress on nanotechnology-based drugs in HCC treatment, and discussed the future perspectives and challenges of nanotechnology-based drugs in HCC treatment.

Biomaterials-based additive manufacturing for customized bioengineering in management of otolaryngology: a comprehensive review

Three-dimensional (3D)/four-dimensional (4D) printing, also known as additive manufacturing or fast prototyping, is a manufacturing technique that uses a digital model to generate a 3D/4D solid product. The usage of biomaterials with 3D/4D printers in the pharma and healthcare industries is gaining significant popularity. 3D printing has mostly been employed in the domain of otolaryngology to build portable anatomical models, personalized patient-centric implants, biologic tissue scaffolds, surgical planning in individuals with challenging conditions, and surgical training. Although identical to 3D printing technology in this application, 4D printing technology comprises a fourth dimension of time. With the use of 4D printing, a printed structure may alter over time under various stimuli. Smart polymeric materials are also generally denoted as bioinks are frequently employed in tissue engineering applications of 3D/4D printing. In general, 4D printing could significantly improve the safety and efficacy of otolaryngology therapies. The use of bioprinting in otolaryngology has an opportunity to transform the treatment of diseases influencing the ear, nose, and throat as well as the field of tissue regeneration. The present review briefs on polymeric material including biomaterials and cells used in the manufacturing of patient centric 3D/4D bio-printed products utilized in management of otolaryngology.

Angiogenesis induction as a key step in cardiac tissue Regeneration: From angiogenic agents to biomaterials

Cardiovascular diseases are the leading cause of death worldwide. After myocardial infarction, the vascular supply of the heart is damaged or blocked, leading to the formation of scar tissue, followed by several cardiac dysfunctions or even death. In this regard, induction of angiogenesis is considered as a vital process for supplying nutrients and oxygen to the cells in cardiac tissue engineering. The current review aims to summarize different approaches of angiogenesis induction for effective cardiac tissue repair. Accordingly, a comprehensive classification of induction of pro-angiogenic signaling pathways through using engineered biomaterials, drugs, angiogenic factors, as well as combinatorial approaches is introduced as a potential platform for cardiac regeneration application. The angiogenic induction for cardiac repair can enhance patient treatment outcomes and generate economic prospects for the biomedical industry. The development and commercialization of angiogenesis methods often involves collaboration between academic institutions, research organizations, and biomedical companies.

Revisiting Retinal Degeneration Hallmarks: Insights from Molecular Markers and Therapy Perspectives

Visual impairment and blindness are a growing public health problem as they reduce the life quality of millions of people. The management and treatment of these diseases represent scientific and therapeutic challenges because different cellular and molecular actors involved in the pathophysiology are still being identified. Visual system components, particularly retinal cells, are extremely sensitive to genetic or metabolic alterations, and immune responses activated by local insults contribute to biological events, culminating in vision loss and irreversible blindness. Several ocular diseases are linked to retinal cell loss, and some of them, such as retinitis pigmentosa, age-related macular degeneration, glaucoma, and diabetic retinopathy, are characterized by pathophysiological hallmarks that represent possibilities to study and develop novel treatments for retinal cell degeneration. Here, we present a compilation of revisited information on retinal degeneration, including pathophysiological and molecular features and biochemical hallmarks, and possible research directions for novel treatments to assist as a guide for innovative research. The knowledge expansion upon the mechanistic bases of the pathobiology of eye diseases, including information on complex interactions of genetic predisposition, chronic inflammation, and environmental and aging-related factors, will prompt the identification of new therapeutic strategies.

Adenovirus-Based Gene Therapy for Bone Regeneration: A Comparative Analysis of In Vivo and Ex Vivo BMP2 Gene Delivery

Adenovirus-mediated gene therapy is a promising tool in bone regenerative medicine. In this work, gene-activated matrices (GAMs) composed of (1) polylactide granules (PLA), which serve as a depot for genetic constructs or matrices for cell attachment, (2) a PRP-based fibrin clot, which is a source of growth factors and a binding gel, and (3) a BMP2 gene providing osteoinductive properties were studied. The study aims to compare the effectiveness of in vivo and ex vivo gene therapy based on adenoviral constructs with the BMP2 gene, PLA particles, and a fibrin clot for bone defect healing. GAMs with Ad-BMP2 and MSC(Ad-BMP2) show osteoinductive properties both in vitro and in vivo. However, MSCs incubated with GAMs containing transduced cells showed a more significant increase in osteopontin gene expression, protein production, Alpl activity, and matrix mineralization. Implantation of the studied matrices into critical-size calvarial defects after 56 days promotes the formation of young bone. The efficiency of neoosteogenesis and the volume fraction of newly formed bone tissue are higher with PLA/PRP-MSC(Ad-BMP2) implantation (33%) than PLA/PRP-Ad-BMP2 (28%). Thus, ex vivo adenoviral gene therapy with the BMP2 gene has proven to be a more effective approach than the in vivo delivery of gene constructs for bone regeneration.

Regeneration or Scarring Derive from Specific Evolutionary Environmental Adaptations of the Life Cycles in Different Animals

The ability to heal or even regenerate large injuries in different animals derives from the evolution of their specific life cycles during geological times. The present, new hypothesis tries to explain the distribution of organ regeneration among animals. Only invertebrates and vertebrates that include larval and intense metamorphic transformations can broadly regenerate as adults. Basically, regeneration competent animals are aquatic while terrestrial species have largely or completely lost most of the regeneration ability. Although genomes of terrestrial species still contain numerous genes that in aquatic species allow a broad regeneration ("regenerative genes"), the evolution of terrestrial species has variably modified the genetic networks linking these genes to the others that evolved during land adaptation, resulting in the inhibition of regeneration. Loss of regeneration took place by the elimination of intermediate larval phases and metamorphic transformations in the life cycles of land invertebrates and vertebrates. Once the evolution along a specific lineage generated species that could no longer regenerate, this outcome could not change anymore. It is therefore likely that what we learn from regenerative species will explain their mechanisms of regeneration but cannot or only partly be applied to non-regenerative species. Attempts to introduce "regenerative genes" in non-regenerative species most likely would disorder the entire genetic networks of the latter, determining death, teratomas and cancer. This awareness indicates the difficulty to introduce regenerative genes and their activation pathways in species that evolved genetic networks suppressing organ regeneration. Organ regeneration in non-regenerating animals such as humans should move to bio-engineering interventions in addition to "localized regenerative gene therapies" in order to replace lost tissues or organs.